One who believes in the Son has eternal life, but one who disobeys{The same word can be translated "disobeys" or "disbelieves" in this context.} the Son won't see life, but the wrath of God remains on him."
The events in John’s narrative of Jesus’ first visit to Jerusalem (John 2:13 to John 3:36) set the tone for Jesus’ ministry, particularly His later occasions of ministry in Jerusalem (ch. 5; John 7:10 to John 10:42; John 12:12-50). The conflict between belief and unbelief begins to surface here.