1 John 2:5

but whoso keepeth his word, in him verily hath the love of God been perfected. Hereby we know that we are in him:

Whoso keepeth his word ... This is identical in meaning with "if we keep his commandments" (1 John 2:3).

The love of God has been perfected ... Here is another glimpse of that absolute perfection which is the goal of all Christian living, mentioned by Jesus in Matthew 5:48, and referred to by all the New Testament writers. Although unattainable by humans in their own strength, it will nevertheless be achieved in them and for them by means of their being "in Christ" and thereby partaking of the absolute perfection of the Saviour himself (Colossians 1:28). Significantly, the necessity of being "in him" is the concluding thought of this verse.

Love of God ... This is objective, referring not to God's love of man, but to "man's love to God."[15]

Hereby we know that we are in him ... Although the grammatical structure makes "God" the antecedent of "in him" in this place, still the meaning is "in Christ," no man ever having been "in God" by any other means than that of his having been baptized into the spiritual body of Christ. Being "in God" and "in Christ" are exactly one and the same thing. This thought comes to the foreground a number of times in this letter. Thus John placed the same importance and priority upon this conception that are given to it in the writings of the apostle Paul who used the expression "in Christ" or its equivalent some 169 times. The idea of the corporate body of Christ was not developed either by Paul or by John but is derived from the Lord himself who gave the foundation of it in such teaching as that of his being the vine, the apostles being the branches, and all Christians abiding "in him," that is, "in the true vine" (John 15). Since one enters "him" through primary obedience (baptism), it is the true continuity of that holy relationship that John here declared us to "know" if we keep his word.

Before leaving this verse, we should note that love ([Greek: agape]) is one of the leading concepts, recurring again and again in John's work. In this letter alone, "it occurs 18 times, more than in any other New Testament book, 1Corinthians being 2nd with 14 times. In a book so short this is very significant."[16] As used in this place, the love to God is not a mere emotional response, "it is the response lived out in obedience. Love delights to do God's will."[17]

[15] J. R. Dummelow, Commentary on the Holy Bible (New York: The Macmillan Company, 1937), p. 1056.

[16] Leon Morris, op. cit., p. 1263.

[17] Ibid.