We should be like God.

Leviticus 11:45 (NASB95)
“For I am the LORD who brought you up from the land of Egypt to be your God; thus you shall be holy, for I am holy.”

This sentiment is repeated a few times in Leviticus as well by Peter (1Pe 1:15).

I think we ought to be like God—not as Adam and Eve in Eden, but as regards to sin in general (and, perhaps, lying in particular). I would argue that God never wants us to sin. That doesn’t sound controversial, but compared to the idea of a higher obligation suspending a lower one, the obligation not to sin trumps nearly everything else, including all the reasons one could give for why/when it’s OK to lie.

The Biblical authors are very clear that God does not and cannot sin, nor is He tempted to sin.

1 John 1:5 (NASB95)
This is the message we have heard from Him and announce to you, that God is Light, and in Him there is no darkness at all.

James 1:13 (NASB95)
Let no one say when he is tempted, “I am being tempted by God”; for God cannot be tempted by evil, and He Himself does not tempt anyone.

Does God Lie?

On the surface, this sounds like a no-brainer. Consider these strong answers to the question.

Numbers 23:19 (NASB95) (emphasis added)
“God is not a man, that He should lie, Nor a son of man, that He should repent; Has He said, and will He not do it? Or has He spoken, and will He not make it good?”

Titus 1:1-3 (NASB95) (emphasis added)
Paul, a bond-servant of God and an apostle of Jesus Christ, for the faith of those chosen of God and the knowledge of the truth which is according to godliness, in the hope of eternal life, which God, who cannot lie, promised long ages ago, but at the proper time manifested, even His word, in the proclamation with which I was entrusted according to the commandment of God our Savior,...

Hebrews 6:17-18 (NASB95) (emphasis added)
In the same way God, desiring even more to show to the heirs of the promise the unchangeableness of His purpose, interposed with an oath, so that by two unchangeable things in which it is impossible for God to lie, we who have taken refuge would have strong encouragement to take hold of the hope set before us.

A simple reading of these passages seems to make a very strong case that God does not lie.

What about delusions and deceptions?

Consider these passages.

1 Kings 22:19-22 (NASB95)
Micaiah said, “Therefore, hear the word of the LORD. I saw the LORD sitting on His throne, and all the host of heaven standing by Him on His right and on His left. The LORD said, ‘Who will entice Ahab to go up and fall at Ramoth-gilead?’ And one said this while another said that. Then a spirit came forward and stood before the LORD and said, ‘I will entice him.’ 22 “The LORD said to him, ‘How?’ And he said, ‘I will go out and be a deceiving spirit in the mouth of all his prophets.’ Then He said, ‘You are to entice [him] and also prevail. Go and do so.’”

Can God employ deceit and still not lie?

We don’t know who the “spirit who came forward” was, but it’s at least conceivable that it could have been Satan, who is permitted to converse with God as well as accomplish God’s will (though probably not desiring to do so) using his own devices (cf. Job 1-2).

2 Thessalonians 2:11-12 (NASB95)
For this reason God will send upon them a deluding influence so that they will believe what is false, in order that they all may be judged who did not believe the truth, but took pleasure in wickedness.

If God sends a delusion, is that different than lying?

I don’t have a succinct answer to this, but I point to a parallel question for which it is difficult to find a brief answer: How can sin exist if God didn’t “create” it? Can God allow or permit something without causing it or endorsing it (or thinking of it as “good”)? The simple answer to the latter question is yes (the proof is left as an exercise to the reader), and so I conclude that God can permit people to be deceived/deluded (as if it’s the result of their own sin) without actually “doing it Himself.”

Does God ever command or commend anyone for lying?

The examples given in other answers are the most pertinent for answering this question.

I would argue that in none of them is the act of lying, itself, ever endorsed by the Biblical authors.

God blesses the hebrew midwives, who disobeyed Pharaoh and (arguably) lied about it, because “the midwives feared God.” (Ex 1:21;NASB95).

Rahab is praised by the Hebrews writer because “she had welcomed the spies in peace” (Heb 11:31;NASB95). James says that she was “justified by works” (Jas 2:25;NASB95) without going into detail about which works. You could perhaps read either of these statements as including her lies (argued by others not to be lies—I’m assuming the worst here) to the men of Jericho, but I don’t think that is the only reasonable way to read it.

Does God ever commend anyone for not lying?

There are plenty of examples of people being punished for lying (e.g. (Hos 10:3, Ananias and Sapphira (Acts 5:1-16)). This is not controversial.

How are people praised for not lying?

Here are the most telling examples I can think of.

Psalm 32:2 (NASB95)
How blessed is the man to whom the LORD does not impute iniquity, And in whose spirit there is no deceit!

Isaiah 53:9 (NASB95)
His grave was assigned with wicked men, Yet He was with a rich man in His death, Because He had done no violence, Nor was there any deceit in His mouth.

This passage is quoted by Peter (1Pe 2:22), specifically referring to Jesus (though Isaiah is doing the same).

John 1:47 (NASB95)
Jesus saw Nathanael coming to Him, and said of him, “Behold, an Israelite indeed, in whom there is no deceit!”

What should we be like?

Considering the explicit praise of being without deceit, the lack of praise for deceit, the commandments against (certain kinds of ?) deceit, our obligation to be like God (in holiness, at least), and the fact that God does not lie, I think it reasonable to conclude that we should not lie or deceive.

There are some niche questions about deception (e.g. playing a game of chess, sports plays, etc.) that require some care, but I don’t think any of those things should be our guiding principles. I use the example of Corrie Ten Boom’s sister as a legitimate example of why refusing to lie is the better choice, because it demonstrates our trust in God to bring about a good outcome while still refusing to sin.

I don’t dismiss any of the questions raised in other posts as trivial. I’m just not going to deal with them in this (sorry) long answer.

The Hebrew midwives lied (Exodus 1:15-19) or should we rather say “lied” to or misled Pharaoh. For it they were blessed by God (Ex 1:20-21). Also, Rahab misled (Joshua 2:3-6). She “lied” because of her faith... according to the New Testament she is one of the heroines of faith in the Old Testament (Hebrews 11:31).

In these cases there is no hint the “lies” were morally wrong. Quite the opposite: it is already pointed out the midwives were blessed for what they did; the behaviour of Rahab also is specifically picked out, not for condemnation, but, for commendation (James 2:25).

In more recent times Corrie Ten Boom “lied”. Nazis knock on her door and would ask her if she was hiding any Jews. You can read the book and watch the film "The Hiding Place".

Some theologians have argued in favour of situational ethics where “the end justifies the means” and where "love" is the only moral absolute and the only guiding principle of Christian ethics, where the Decalogue is superseded. Such an approach does not do justice to the significance the Ten Commandments are given in Scripture.

I shall quote exclusively from “Evangelical Ethics – Issues Facing the Church Today” by John Jefferson Davis (2nd edition, 1993). The author is Professor of Systematic Theology and Christian Ethics at Gordon-Conwell Theological Seminary. On the issue in question he follows in the footsteps of Charles Hodge (“Systematic Theology”) and Norman Geisler (“Options in Contemporary Christian Ethics”, Grand Rapids: Baker, 1981, pages 81-101).

Davis calls the ethical approach he holds to as “contextual absolutism”. It is, he says, very similar to the approach Geisler calls “graded absolutism”.

The term “contextual absolutism” contains the implicit reminder that the moral absolutes of Scripture need to be understood and applied within their proper context. Some normal or prima facie duties may not be actual duties when all things are taken into consideration. As Charles Hodge, the famous conservative theologian of the previous century, has noted, occasionally a HIGHER OBLIGATION SUSPENDS a LOWER one [AJS: Emphasis mine]. Several examples may help to make this point clear.

There are a number of illustrations in Scripture of the principle that obedience to God takes precedence over the normal obligation to obey government (Romans 13:1). The Hebrew midwives refused to obey the command of the Pharaoh to kill the male Hebrew infants, and God blessed them for their courage (Ex 1:15-17). In the early church the apostles refused to obey the orders of the Jewish authorities to refrain from preaching the gospel, replying, “We must obey God rather than men” (Acts 5:29). Daniel and his friends were willing to face martyrdom rather than obey Nebuchadnezzar’s command to worship the idol (Dan 3:17-18). When the laws of God conflict with the laws of men, human laws must yield to the higher authority of God.

The Bible endorses the principle that one human life is of far greater value than physical property or possessions. One human life or soul is more valuable in God’s sight than the entire physical world (cf Matt 16:26: “What does it profit a man if he gains the whole world and forfeits his life?”). A fireman who breaks down the door of a burning home in order to save a child’s life is not guilty of breaking the eighth commandment’s prohibition of stealing, which normally applies to the wilful destruction of another’s property. In such an emergency, any reasonable person, if asked, would give permission for the destruction of property in order to save a life. One can suppose that an implied consent justifies the fireman’s action.

Cases involving possible conflicts between telling the truth and saving lives are more difficult to analyze. When Rahab the harlot (Joshua 2:1-7), for example, spoke falsehood to protect the Israelite spies, was she choosing “the lesser of two evils”, or a course of action that was acceptable to God?

Charles Hodge has pointed out that in such cases one’s definition of a lie is crucial. Not every act of deception is the moral equivalent of a lie; a lie involves “an intention to deceive when we are expected and bound to speak the truth.” In certain contexts full disclosure is not expected. In [American] football, for example, a quarterback is not expected to reveal his plays to the opposition; he intentionally tries to deceive the opposing defence when he fakes to the fullback but passes to the wide receiver. In warfare … deception by camouflage and other means is the “name of the game”.

It could be argued that Rahab, living in the context of war … and having shifted her allegiance … to the God of Israel … had no obligation to make full disclosure to the soldiers of Jericho. Her higher duty to protect the lives of the soldiers suspended the prima facie duty to tell the truth, and her course of action was acceptable to God … her actions rather than being the lesser of two evils were actually good.

It is never morally acceptable to lie.

But the fearful, and unbelieving, and the abominable, and murderers, and who*emongers, and sorcerers, and idolaters, and all liars, shall have their part in the lake which burneth with fire and brimstone: which is the second death. [Revelation 21:8 KJV]

Not just 'some liars' but 'all liars', will have their part in the lake of fire.

Some justify telling lies because (they claim) 'people in the bible told lies' in order, they say, to protect others.

They are mistaken.

There are examples in scripture of people who chose very carefully what they uttered when they needed to protect other people.

Careful examination of the literal meaning of the recorded words in scripture reveals that no lie was told, during certain events.

The Hebrew midwives (later rewarded by the Almighty) carefully worded their statement :

before the midwife cometh in, they have borne [Young's Literal : Exodus 1:19].

The midwives could be standing outside in the yard, quite truthfully.

And Rahab :

I have not known whither the men have gone [Young's Literal : Joshua 2:5]

She left them somewhere, yes, but she has no knowledge of where they are now, of a certainty.

So also the woman who covered the well and hid the men :

They passed over the brook of water [Young's Literal 2 Samuel 17:20 ]

Indeed, they were suspended over it.

Nobody is 'lying'. They are stating facts, on a need to know basis. The proposition (that people are lying) has not been proven.

It is quite proper to be discrete , to withhold information from someone whose motive is to use that information in order to commit murder, for example.

That is no sin. It is not a lie. They do not have a right to such information if they are going to use that information to murder people.

One does not need to lie. One can be discrete about what information to give them.

I repeat, 'all liars' shall find their place in a lake of fire.

It is never 'morally acceptable' to tell a lie.

Ever.

When is it morally acceptable to lie?

My initial response to this question question was: It is complicated!

I am not going to regurgitate the information posted in the excellent answers of Grateful Disciple, Andrew Shanks or Nigel J, but rather give a response with a twist.

Many Christians believe that all lying is morally sinful. Even St. Thomas states this, although he admits that the gravity of the sin will vary according to the situation.

Lying with words in jest are certainly not as serious as about lying with deliberate intentions of deception.

Funny how in a court of law we have uphold the truth, yet in some countries like the USA, it is morally acceptable for detectives to lie to suspects in order to find the truth. I really never understood the reasoning behind it, but the law allows it.

The moral question of lying is one of the most interesting and most difficult to resolve perfectly and precisely. It has occupied the attention of moral theologians since the Patristic Age, yet we still don’t have a complete understanding of what “lying” means. Most of us have a deep intuition that it is morally acceptable to speak falsely in some circumstances, but the Church has not yet offered an official explanation as to why this is the case. Presumably, there is room for doctrinal development here, and I find the question fascinating.

Well in the Catechism of the Catholic Church we have a definition of lying that has a loophole of sorts.

2483 Lying is the most direct offense against the truth. To lie is to speak or act against the truth in order to lead into error someone who has the right to know the truth. By injuring man's relation to truth and to his neighbor, a lie offends against the fundamental relation of man and of his word to the Lord.*

Obviously we must try never never to lie, but if we know that the person we are engaged in conversation has no moral right to know the truth, we may be permitted to deceive the person in question!

I know this will not fly with some Christians, but if believers hiding Jews from the Nazis during WWII, would really have a dilemma if the Germans nocked at their doors and asked them if they were housing Jews.

The vast majority of well-formed Catholics would answer this question in the negative. Under these circumstances, it is perfectly permissible to deceive the Nazis at the door. But even well-formed Catholics can’t explain why this is the case, or at least they can’t explain it in a way which is universally-accepted by sound moral theologians down through the ages, nor in a way that has yet been endorsed by the Magisterium of the Church. Most of us believe we can and indeed should lie under these circumstances, but we don’t know exactly why. This problem so agitated Catholic thinkers during the 17th, 18th and 19th centuries that their less subtle Protestant brethren began to question whether Catholics even believe in telling the truth in all situations.

Not everyone has the right to know the truth.

For further information, the following may be of interest:

• Lying (Catholic Encyclopaedia)
• Is it ever justifiable to lie?
• Is It Ever Right to Lie?
• Catechismus Catholicae Ecclesiae