Does the Bible teach us to be truthful or nice?

This is one definition of “nice”:

nice definition: 1. pleasant, enjoyable, or satisfactory: 2. pleasantly: 3. kind, friendly, or polite

However, when it comes to Christians, there are plenty Bible verses about truth. Ephesians 4:15 exhorts us to speak the truth in love.

In other words, we do not flinch from speaking God's truth, the truth about Christ Jesus and salvation. But we must speak that truth in love.

Just being "nice" might prevent us from speaking God's truth. For example, we now live in a world where Christians are being singled out for sharing their Christian values. The world wants us to compromise and keep our opinions to ourselves.

Jesus never suggested we should lie, or twist the truth, and nor did he himself ever flinch from speaking the truth, even when he knew speaking the truth would result in his death.

The greatest disservice we can do to any person is to avoid speaking the truth about Christ Jesus, our Lord and our Saviour. By trying to avoid hurting anybody's feelings (when it comes to spiritual truth) we are denying our Lord and our Saviour.

Of course, it is HOW we speak truth that matters, and that boils down to our motivation. My mother used to say that if a response was neither necessary nor kind, then it would be better to say nothing. She was a very nice woman.

EDIT: Additional biblical references on the subject of how Christians should speak truth in love:

On many occasions Jesus spoke uncomfortable truths in love. He confronted the rich young ruler about his attachment to his wealth (Mark 10:17-27), and he spoke to the woman by the well about her sexual behaviour (John 4:1-26), with amazing results (John 4:39-42).

To conclude, Christian truth and love go hand in hand and should never be separated. If we speak the truth without love, we are harsh and ungracious and fall far short of the example of Christ Jesus. If we act in a supposedly ‘loving’ manner without basing what we say and do on the truth, we betray Christ and confirm the other person in their error.

P.S. Christ-like love has a divine source and goes way beyond just being "nice".

Gal 1:10 NLT Obviously, I'm not trying to win the approval of people, but of God. If pleasing people were my goal, I would not be Christ's servant.

Matt 10:34-37 NJB

³⁴'Do not suppose that I have come to bring peace to the earth: it is not peace I have come to bring, but a sword. ³⁵For I have come to set son against father, daughter against mother, daughter-in-law against mother-in-law; ³⁶a person's enemies will be the members of his own household. ³⁷'No one who prefers father or mother to me is worthy of me. No one who prefers son or daughter to me is worthy of me.

The NT records the first preaching of the Gospel like this, from John's mouth:

Matt 3:2-10 NHEB

²and saying, "Repent, for the kingdom of heaven is near." ³For this is he who was spoken of by Isaiah the prophet, saying, "The voice of one who calls out in the wilderness, 'Prepare the way of the Lord. Make his roads straight.'" ⁴Now John himself wore clothing made of camel's hair and with a leather belt around his waist, and his food was locusts and wild honey. ⁵Then people from Jerusalem, all of Judea, and all the region around the Jordan went out to him, ⁶and they were baptized by him in the Jordan river, confessing their sins. ⁷But when he saw many of the Pharisees and Sadducees coming for his baptism he said to them, "You offspring of vipers, who warned you to flee from the wrath to come? ⁸Therefore bring forth fruit worthy of repentance, ⁹and do not think to yourselves, 'We have Abraham for our father,' for I tell you that God is able to raise up children to Abraham from these stones. ¹⁰"Even now the axe lies at the root of the trees. Therefore, every tree that does not bring forth good fruit is cut down, and cast into the fire.

I don't think John would've been beheaded, Jesus crucified and all the apostles and prophets killed if they would've believed in a "nice" teaching and palatable lifestyle.

Proverbs 1:20-26: “Wisdom calls aloud in the street. She utters her voice in the public squares. She calls at the head of noisy places. At the entrance of the city gates, she utters her words: “How long, you simple ones, will you love simplicity? How long will mockers delight themselves in mockery, and fools hate knowledge? Turn at my reproof. Look, I will pour out my spirit on you. I will make known my words to you. Because I have called, and you have refused; I have stretched out my hand, and no one has paid attention; but you have ignored all my counsel, and wanted none of my reproof; I also will laugh at your disaster. I will mock when calamity overtakes you;”

This explains the prophet Elijah’s mocking the false prophets of Baal, since he was only imitating Yahweh his God at this point: 1 Kings 18:20-29, Philippians 3:2-3; Titus 1:10-13 ; 2Peter 2:12, 19-22. In this the apostles were imitating the language of the Lord Jesus:

"Do not give dogs what is sacred; do not throw your pearls to pigs. If you do, they may trample them under their feet, and then turn and tear you to pieces." Matthew 7:6. Cf Romans 12:17-21, Colossians 4:6,

Ecclesiastes 3:1-8

¹For everything there is a season, and a time for every purpose under heaven: ²a time to be born, and a time to die; a time to plant, and a time to pluck up that which is planted; ³a time to kill, and a time to heal; a time to break down, and a time to build up; ⁴a time to weep, and a time to laugh; a time to mourn, and a time to dance; ⁵a time to cast away stones, and a time to gather stones together; a time to embrace, and a time to refrain from embracing; ⁶a time to seek, and a time to lose; a time to keep, and a time to cast away; ⁷a time to tear, and a time to sew; a time to keep silence, and a time to speak; ⁸a time to love, and a time to hate; a time for war, and a time for peace.

Since when are being nice and being truthful in contradistinction? Being nice is nice, but to speak the truth in love is nicer by far.

Your confusion may lie in not making a distinction between being honest and being truthful. Being honest can sometimes border on being cruel and unkind. The wife who asks her husband if the blue dress makes her look fat is not looking for unvarnished honesty from her husband, neither does she want a bald lie.

Kindness, diplomacy, and tailoring one's comments to the hearer are all very biblical. The husband need not say "I much prefer the red dress on you," thus skirting the issue. I suggest he say instead, "Hun, I think you look just fine. If you're not comfortable with the blue dress, find a frock you ARE comfortable with. I love you just as you are."

When a child who just finished playing their first piano solo before an audience that includes his or her parents, the child might ask the parents afterwards, "Mom, Dad, how did you like my solo?" Even if the child made lots of mistakes, the kind thing for the parents to say to their child might be, "We enjoyed it just fine. We're proud of you. We also think you are improving. Just keep on practicing."

Because Jesus came from the Father, full of grace and truth, his followers need to emulate him in their interactions with people in general and believers in particular. Grace needs to precede truth, and they complement each other very nicely!

The Bible teaches being truthful, even if it hurts.

Faithful are the wounds of a friend; but the kisses of an enemy are deceitful. (Proverbs 27:6, KJV)

Let the righteous smite me; it shall be a kindness: and let him reprove me; it shall be an excellent oil, which shall not break my head: for yet my prayer also shall be in their calamities. (Psalm 141:5, KJV)

Reprove not a scorner, lest he hate thee: rebuke a wise man, and he will love thee. (Proverbs 9:8, KJV)

Better by far to hear the truth kindly spoken from the lips of a friend, than to have it hurled mercilessly from those of an enemy; and no true friend will withhold the truth.