And this is his commandment,.... Having mentioned the keeping of the commandments of God, the apostle proceeds to show what they are; that they are faith in Christ, and love to one another; which two are reduced to one, because they are inseparable; where the one is, the other is; faith works by love.
That we should believe on the name of his Son Jesus Christ; Christ is the object of faith, and he is no, as he is Jesus, a Saviour; faith deals with him as such, and will have no other Saviour but he: and now to believe in him, is not merely to believe that he is the Son of God, the true Messiah, the Saviour of the world, that he is come in the flesh, has suffered, and died, and rose again from the dead, is ascended into heaven, and is set down at the right hand of God, makes intercession for his people, and will come again to judge the quick and dead; but it is to go forth in special and spiritual acts upon him, such as looking at him, coming to him, venturing on him, trusting in him for life and salvation, committing all into his hands, and expecting all from him.