These are Bible promises about friendship(All Bible texts are the New King James Version.)
"Do not be deceived: 'Evil company corrupts good habits.” - 1 Corinthians 15:33
"Then Elijah said to Elisha, 'Stay here, please, for the Lord has sent me on to Bethel.'
But Elisha said, “As the Lord lives, and as your soul lives, I will not leave you!” So they went down to Bethel." - 2 Kings 2:2
"Now when Job’s three friends heard of all this adversity that had come upon him, each one came from his own place—Eliphaz the Temanite, Bildad the Shuhite, and Zophar the Naamathite. For they had made an appointment together to come and mourn with him, and to comfort him." - Job 2:11
"He who walks with wise men will be wise,
But the companion of fools will be destroyed. " - Proverbs 13:20
"Where no oxen are, the trough is clean;
But much increase comes by the strength of an ox.
A faithful witness does not lie,
But a false witness will utter lies.
A scoffer seeks wisdom and does not find it,
But knowledge is easy to him who understands." - Proverbs 14:4-6
"A friend loves at all times,
And a brother is born for adversity." - Proverbs 17:17
"A man who has friends must himself be friendly,
But there is a friend who sticks closer than a brother." - Proverbs 18:24
"Listen to counsel and receive instruction,
That you may be wise in your latter days. " - Proverbs 19:20
"Make no friendship with an angry man,
And with a furious man do not go,
Lest you learn his ways
And set a snare for your soul. " - Proverbs 22:24-25
" A wise man is strong,
Yes, a man of knowledge increases strength;" - Proverbs 24:5
"Open rebuke is better
Than love carefully concealed.
Faithful are the wounds of a friend,
But the kisses of an enemy are deceitful." - Proverbs 27:5, 6
"Two are better than one,
Because they have a good reward for their labor.
10 For if they fall, one will lift up his companion.
But woe to him who is alone when he falls,
For he has no one to help him up." - Ecclesiastes 4:9-10
"And just as you want men to do to you, you also do to them likewise." - Luke 6:31
"This is My commandment, that you love one another as I have loved you. Greater love has no one than this, than to lay down one’s life for his friends. You are My friends if you do whatever I command you. No longer do I call you servants, for a servant does not know what his master is doing; but I have called you friends, for all things that I heard from My Father I have made known to you. " - John 15:12-15
"Therefore, as the elect of God, holy and beloved, put on tender mercies, kindness, humility, meekness, longsuffering;bearing with one another, and forgiving one another, if anyone has a complaint against another; even as Christ forgave you, so you also must do. But above all these things put on love, which is the bond of perfection." - Colossians 3:12-14