What is the Biblical basis for Conditional Election?

There are too many scriptures that show the conditional nature of salvation to meaningfully review here. However, let's focus on one common thread in scripture: perseverance. Scripture teaches that it is those who persevere unto the end that are saved, that that which is promised to us is contingent upon this.

Hebrews 10:36 You need to persevere so that when you have done the will of God, you will receive what he has promised.

1 Timothy 4:16 Watch your life and doctrine closely. Persevere in them, because if you do, you will save both yourself and your hearers.

James 1:12 Blessed is the one who perseveres under trial because, having stood the test, that person will receive the crown of life that the Lord has promised to those who love him.

2 Timothy 4:6-8 For I am already being poured out like a drink offering, and the time for my departure is near. 7 I have fought the good fight, I have finished the race, I have kept the faith. 8 Now there is in store for me the crown of righteousness, which the Lord, the righteous Judge, will award to me on that day—and not only to me, but also to all who have longed for his appearing.

Also, a bonus scripture - because I think it is very powerful at speaking to not just our responsibility to keep God's commands, but also to our personal ability to do so. To keep the commands is a choice with corresponding consequences/rewards:

Deutoronomy 30:11-16 Now what I am commanding you today is not too difficult for you or beyond your reach. 12 It is not up in heaven, so that you have to ask, “Who will ascend into heaven to get it and proclaim it to us so we may obey it?” 13 Nor is it beyond the sea, so that you have to ask, “Who will cross the sea to get it and proclaim it to us so we may obey it?” 14 No, the word is very near you; it is in your mouth and in your heart so you may obey it. 15 See, I set before you today life and prosperity, death and destruction. 16 For I command you today to love the Lord your God, to walk in obedience to him, and to keep his commands, decrees and laws; then you will live and increase, and the Lord your God will bless you in the land you are entering to possess.

I am not a fan of the term "conditional election" as I believe that "election" has been misunderstood and polarized but the actuality of human choice within the framework of God's complete foreknowledge can be biblically established. As usual there are lots of "proof texts" for this position as well as it's antithesis: Here are a few that, I believe, establish the scriptural basis from which to reason.

God knows the end from the beginning. If we do not tack on any limitations to this statement and let His foreknowledge be as infinite as He is, then He can easily have foreknown each and every human choice before He created anything. Some believe that such foreknowledge eradicates the possibility of actual choice but that conclusion is by no means inescapable.

Remember the former things of old: for I am God, and there is none else; I am God, and there is none like me, Declaring the end from the beginning, and from ancient times the things that are not yet done, saying, My counsel shall stand, and I will do all my pleasure: - Isaiah 46:9-10

Election is according to God's foreknowledge. This is clearly stated in a few places. Peter most directly states it and Paul indicates a progression starting with foreknowledge, through calling, and ending with glorification. Some will try to narrow the definition of "foreknown" to the knowledge born of personal intimacy or some such thing but this does nothing to disconnect the possibility of human choice from the equation.

Elect according to the foreknowledge of God the Father, through sanctification of the Spirit, unto obedience and sprinkling of the blood of Jesus Christ: Grace unto you, and peace, be multiplied. - 1 Peter 1:2

And we know that all things work together for good to them that love God, to them who are the called according to his purpose. For whom he did foreknow, he also did predestinate to be conformed to the image of his Son, that he might be the firstborn among many brethren. Moreover whom he did predestinate, them he also called: and whom he called, them he also justified: and whom he justified, them he also glorified. - Romans 8:28-30

The invitation is genuine. There are many commands and invitations to turn away from sin and turn toward the living God which are direct or implied. These all lose their genuineness if the manner of our response is pre-programmed rather than foreknown. For instance, God has commanded all men everywhere to repent (Acts 17:30) but, if He actively withholds the ability to repent from some, there is little purpose in the command to them.

Come unto me, all ye that labour and are heavy laden, and I will give you rest. Take my yoke upon you, and learn of me; for I am meek and lowly in heart: and ye shall find rest unto your souls. - Matthew 11:28-29

Condemnation is also linked to choice. If the following passage is read with the understanding that all the "loving", "hating", "believing" (or not), "doing", and "coming" are not acted upon human choices but are, instead, inescapably pre-programmed activities then the explanation of the nature of the condemnation becomes garbled.

He that believeth on him is not condemned: but he that believeth not is condemned already, because he hath not believed in the name of the only begotten Son of God. And this is the condemnation, that light is come into the world, and men loved darkness rather than light, because their deeds were evil. For every one that doeth evil hateth the light, neither cometh to the light, lest his deeds should be reproved. But he that doeth truth cometh to the light, that his deeds may be made manifest, that they are wrought in God. - John 3:19-21

The Prodigal Son. Reading this parable with the understanding that the younger son did not actually choose to demand his portion of the inheritance, did not choose to squander it, did not choose to return to the father in repentance, etc. not only makes the story nonsensical but also inapplicable: We would have the father rejoicing in the recovery of what he had lost on purpose and then "found" again.

Imagine this re-worked Scripture being the case: "He that believeth on the Son (because God grants the ability) hath everlasting life: and he that believeth not the Son (because God withholds the ability) shall not see life; but the wrath of God abideth on him.".

Conditional Election was a phrase first used in the early 1600s by James Arminius, a Dutch professor who had formulated five main points of doctrine that challenged the Protestant denominations that subscribed to the Belgic and Heidelberg Confessions of Faith - both set squarely on Reformation teachings. Conditional Election was his third point of protest (or 'Remonstrance').

He taught that God laid his hands upon those individuals who he knew, or foresaw, would respond to the gospel. God elected those whom he saw would want to be saved of their own free will, and while in their natural fallen state. Note also that his first point in his Remonstrance was that man was not totally incapable of choosing spiritual good despite the effects of the Fall, and could exercise faith in order to receive the gospel. That would bring him into possession of salvation.

Therefore, the Wikipedia quote you gave is correct in pointing out that the matter of free will is central to this issue.

Reformed Christians of that era responded to Arminius's Remonstrance with their five counter-points, often known by the acrostic, TULIP. However, this quote about the vital connection to the true state of man is worth including:

"There are very few errors and false doctrines of which the beginning may not be traced up to unsound views about the corruption of human nature. Wrong views of a disease will always bring with them wrong views of a remedy. Wrong views of the corruption of human nature will always carry with them wrong views of the grand antidote and cure of that corruption." Bishop J.C. Ryle

If the first point of the Remonstrance is wrong, then that will have a knock-on effect with the other points, especially point two about Unconditional Election. This means that simply quoting a load of scriptures that appear to support that view will be a total waste of time, because the first point (being in error) will skew the whole approach to scripture. If Arminius had wrongly diagnosed the corruption of human nature, then his remedy will remedy nothing, but only serve to prolong the stricken condition.

A list of scriptures about free will with regard to man being elected unto salvation will do nothing to settle the matter, until first the biblical basis for man's true fallen condition has been established. Only then can the question of free will then be understood, from a biblical basis. Whole books have been written about this, and I suggest that the topic is so vast as to preclude any satisfactory answer being given in the very limited scope of this site.