Jesus acted with God’s authority, but he would not give evidence on his own behalf to try to convince the Jews. God was his witness, and Jesus accepted his witness even if the Jews did not (John 5:30-32).
With God as his witness, Jesus needed no other, but if the Jews wanted earthly witnesses, they were available. Jesus gave them three, which would satisfy those who wanted to judge him according to the
requirements for witnesses under Jewish law (cf. Deut 19:15). The first was John the Baptist. His announcement of the coming of the Messiah was like the introduction of a lamp in a dark place. People at first welcomed him, but when they saw that he was calling them to turn from their sinful ways they lost interest (John 5:33-35).
The second witness was the work of Jesus. His miracles were visible proof of the presence and power of the invisible God. But again the Jews did not believe (John 5:36-38). Third, there were the Old Testament Scriptures, which the Jews studied diligently, thinking that by keeping the law they would gain eternal life. Yet their studies did not lead them to accept the Saviour to whom the Scriptures pointed, and therefore they did not receive eternal life (John 5:39-40).
Unlike the Jews, Jesus did not look for human praise. The Jews welcomed those who appointed themselves teachers, but rejected the one whom God appointed (John 5:41-44). If they understood the real meaning of Moses’ law instead of arguing about rules and regulations, they would welcome Jesus. They would see that he was the one to whom Moses’ teaching pointed. In rejecting him they rejected Moses, and so were condemned by the very things that Moses wrote (John 5:45-47).