1 John 5:2

The converse of the truth insisted upon in 1 John 4:20-21 is now stated. There love and obedience to God was shewn to involve love of His children: here love of God's children is said to follow from our love and obedience to God. The two (or three) ideas mutually imply one another. Love to God implies obedience, and either of these implies love of His children, which again implies the other two. In short, love to God and love to the brethren confirm and prove each other. If either is found alone it is not genuine. Fellowship with God and fellowship one with another (1 John 1:3; 1 John 1:7) necessarily exist together. A man may be conscious of kindliness towards others and yet doubt whether he is fulfilling the law of brotherly love. For such the Apostle gives this test, -Do you love God? Do you strive to obey Him? If so your love of others is of the right kind". For the characteristic phrase -keep His commandments" see on 1 John 2:3: but here the true reading seems to be do His commandments, a phrase which occurs nowhere else. This reading is supported by B, all ancient Versions, and several Fathers. Note the -when", or more literally, -whenever" (ὅταν): whenever we love and obey we have fresh evidence that our philanthropy is Christian.