What does John 5:34 mean?

Truth is truth, whether people believe it or not. If Jesus had stood on the streets of Jerusalem and said nothing more than "I am God and the Messiah," this would have been true. As God, there are certain things which only He could know (John 8:14). And, the truth of those claims does not depend on human approval. Of course, because human beings are stubborn and fearful, not many people would have reacted well to such an approach.

Out of love, mercy, and grace, God chose to show humanity that Jesus is the Promised One in many different ways. Jewish legal procedure required two or three witnesses in order to establish a fact (Numbers 35:30; Deuteronomy 17:6). For the sake of our souls, and our salvation, Jesus does not appeal to blind faith. Nor does He reject the normal human need for evidence. Rather, He provides what our weak and limited perspective requires.

Jesus is currently explaining the first of three forms of evidence, which is human testimony. The Pharisees had previously interrogated John the Baptist, who pointed to Jesus as the Promised One (John 1:24–28).

In upcoming verses, Jesus will also refer to evidence through observation—His miracles (John 5:36)—and to the written Scriptures (John 5:39–40).