The Epistles of John, assigned to the writer of the Fourth Gospel and the Revelation, testify that God is love and that love is the test of religion. Second John is written to “the elect lady and her children,” probably a church; Third John is addressed to “the beloved Gaius.”

1 John 3

3:23 And this is his commandment, That we should believe on the name of his Son Jesus Christ, and love one another, as he gave us commandment.