I John 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.”
As typified by King David’s kingship, the “Son” of God, “Jesus Christ” is our “commander” (Isaiah 55:4). Our Commander tells us that “If ye love me, keep my commandments.” (John 14:15); that is, our obedience to His Commandments is testimonial evidence of our love for Him. The very essence of love toward our God is keeping “his commandments” (I John 5:3). Furthermore, our yearnings and efforts to “keep his commandments” gives us personal assurance that “we know him” in a loving way (I John 2:3). Here, John addresses two specific Commandments; first that “we should believe on the name of” God’s “Son Jesus Christ” and then to “love one another”. The word “believe” is in the same etymological chain as “faith”, it connotes putting our “faith” into action. It has essentially the same meaning as this passage: “Yea, a man may say, Thou hast faith, and I have works: shew me thy faith without thy works, and I will shew thee my faith by my works.” (James 2:18). The Commandment to “love one another” is much the same, it is “love” that is known when it is shown by actions. To “believe on the name of his Son Jesus Christ” is to know that “Jesus Christ” is the “Son” of God, that ‘Jehovah is our Salvation’ (“Jesus”), and that “Jesus” was Anointed (“Christ”) by God the Father to “save his people from their sins” (Matthew 1:21); and then to show our “love” to Him by obediently following Him in this present life. A part of showing our “love” to Him is showing that we “love one another”. Showing “love” to “one another” is both “pleasing” to Him (I John 3:22) and it is a practical testimony that we are the Children of God (John 13:35)!