'New Commandment' in the Bible

A new commandment I give to you, that you love one another, just like I have loved you; that you also love one another.

Brothers, I write no new commandment to you, but an old commandment which you had from the beginning. The old commandment is the word which you heard from the beginning.

Again, I write a new commandment to you, which is true in him and in you; because the darkness is passing away, and the true light already shines.

Now I beg you, dear lady, not as though I wrote to you a new commandment, but that which we had from the beginning, that we love one another.