Whosoever shall confess that Jesus is the Son of God - In the true sense, and from the heart. This will always prove that a man is a Christian. But the passage cannot mean that if he merely says so in words, or if he does it insincerely, or without any proper sense of the truth, it will prove that he is a Christian. On the meaning of the sentiment here expressed, see the notes at 1 John 4:2. Compare the notes at Romans 10:10.
Related Commentaries of 1 John 4:15
1 John 4:15
15 Whosoever shall confess that Jesus is the Son of God, God dwelleth in him, and he in God.