This simple statement divides the whole of mankind into two, those who ‘have the Son’ and those who do not, asserting that the first group exclusively are possessors of ‘life’. To grasp the seriousness of this we need to understand firstly what is meant by life, and secondly what it means to ‘have the Son’.
John makes very clear in the previous verse (11) that he is not speaking here about physical life. He summarises God’s testimony about Jesus Christ: ‘God gave us eternal life, and this life is in His Son’. The life being discussed is therefore eternal life. It’s life that goes on forever, not being terminated by physical death. But more, it’s life of a different quality, involving a personal relationship with the living God. Jesus Himself defined it as knowing ‘the only true God, and Jesus Christ Whom [He had] sent’ (John 17:3).
In this passage, John associates ‘having the Son’ with believing – believing what God says about His Son (verse 9), believing in the Son of God (verse 10) and believing in the name of the Son of God (verse 13). This is not a mere acceptance that what God says is true, nor is it simply a belief that the Son of God exists. It is taking on board that the Son of God gave His life on a cross, enduring God’s wrath against sin, so that sinners could be freed from sin’s guilt and given eternal life. It includes believing in the heart that God raised Him to life the third day (Romans 10:9). Essentially, it is taking God at His word, placing absolute trust in Jesus Christ as Saviour from sin, and accepting Him as Lord.
John writes similar words in his Gospel: ‘Whoever believes in the Son has eternal life’ (John 3:36). But he also adds a very solemn warning: ‘whoever does not obey the Son shall not see life, but the wrath of God remains on Him.’
(Quotations from the ESV)
