Galatians 6:4

But let each one examine his own work, and then he will have rejoicing in himself alone, and not in another.

Surrounding context

6:3 For if anyone thinks himself to be something, when he is nothing, he deceives himself.

6:4 But let each one examine his own work, and then he will have rejoicing in himself alone, and not in another.

6:5 For each one shall bear his own load.