John 14:8

Show us the Father - As if he had said, We have seen and adored thee, and our happiness will be complete if thou show us the Father. The demand of Philip was similar to that made by Moses, Exodus 33:18. He wished to see the glory of God. In Peter, James, or John, this would have been inexcusable; but Philip had not seen the transfiguration on the mount. The Jewish history is full of the manifestations which God made of himself, and especially when he gave the law. As Christ was introducing a new law, Philip wished to have an additional manifestation of God.

Lord, show us the Father - Philip here referred to some outward and visible manifestation of God. God had manifested himself in various ways to the prophets and saints of old, and Philip affirmed that if some such manifestation should be made to them they would be satisfied. It was right to desire evidence that Jesus was the Messiah, but such evidence "had been" afforded abundantly in the miracles and teaching of Jesus, and that "should" have sufficed them.