'Assembly' in the Bible

They have testified about your love before the assembly. You will do well to send them forward on their journey in a way worthy of God,

I wrote to the assembly, but Diotrephes, who loves to be first among them, doesn't accept what we say.

Therefore, if I come, I will call attention to his deeds which he does, unjustly accusing us with wicked words. Not content with this, neither does he himself receive the brothers, and those who would, he forbids and throws out of the assembly.