This verse is a further explanation of what John has stated in verse 22.

No one who denies the Son has the Father can be rendered as ‘everyone who denies the Son cannot have the Father,’ ‘if a person denies the Father’s Son, he also cannot have the Father,’ ‘a person cannot have the Father, if he denies his Son.’

“To have the Father” expresses a close and intimate communion with the Father, not the possessing of the Father, of course. Some renderings are ‘to be with the Father,’ ‘to have received the Father,’ ‘to be a child of the Father.’ It is probably an allusion to a favorite expression among the false teachers, who claimed a communion with the Father not polluted by this material world. John counters this by stating who cannot “have the Father” and who can. Only by accepting Jesus Christ, who as man has been part of this material world, can one “have the Father,” that is, have fellowship with God, the Father of Jesus Christ.

He who confesses the Son has the Father also: for the sake of emphasis, again, the thought first expressed in a negative sentence is now repeated in a positive one; see comments on verse 21. The two are parallel but in reverse order. Therefore adjustments or restructurings in the one should have their counterpart in the other.

† “To confess” occurred with “our sins” as goal in 1.9. Here and in 4.3 the goal is personal (“the Son” and “Jesus Christ”), and the verb is used in the sense of declaring openly one’s belief in Christ. In 4.2 and 15 the verb is followed by a clause mentioning a fact about Christ, and has the meaning of declaring openly that one believes that fact. The same Greek verb occurs with the same meaning in 2 John 7, where Revised Standard Version has “acknowledge.”

In the present verse “to confess” is the direct opposite of the preceding “to deny,” and accordingly has to be rendered “to accept” (Good News Translation), ‘not to reject/disown,’ ‘to say “yes” about,’ ‘to say, “I love…,” ’ ‘to declare openly that one believes in.’ In the last mentioned rendering ‘to believe’ (for which see comments on 3.23) should be taken in the sense of believing as true the facts about the Son rather than in the sense of trusting in the Son.

Some versions give different renderings of the two occurrences of “to have the Father”; for example, ‘rejects the Father’ in the preceding, negative clause, and ‘has the Father’ in the present, positive one. In itself ‘to reject’ is an acceptable rendering of “not to have” in this context. Yet such differentiation spoils the reverse parallelism and weakens the allusive character of the expression “to have the Father.” It is therefore unadvisable unless clearly required by receptor language idiom.

Quoted with permission from Haas, C., de Jonge, M. and Swellengrebel, J.L. A Handbook on The First Letter of John. (UBS Handbook Series). New York: UBS, 1972. For this and other handbooks for translators see here .