Proverbs 27:17

Iron sharpens iron,
    and one person sharpens the wits of another.

Ecclesiastes 4:9-12

Two are better than one because they have a good reward for their toil. For if they fall, one will lift up the other, but woe to one who is alone and falls and does not have another to help. Again, if two lie together, they keep warm, but how can one keep warm alone? And though one might prevail against another, two will withstand one. A threefold cord is not quickly broken.

Hebrews 10:24-25

And let us consider how to provoke one another to love and good deeds, not neglecting to meet together, as is the habit of some, but encouraging one another, and all the more as you see the Day approaching.

1 Thessalonians 5:11-14

Therefore encourage one another and build up each other, as indeed you are doing.

But we appeal to you, brothers and sisters, to respect those who labor among you and have charge of you in the Lord and admonish you;esteem them very highly in love because of their work. Be at peace among yourselves. And we urge you, brothers and sisters, to admonish the idlers, encourage the fainthearted, help the weak, be patient with all of them.