23Now when he was in Jerusalem at the passover, in the feastday, many believed in his name, when they saw the miracles which he did.
24 But Jesus did not commit himself unto them, because he knew all men,
25 and needed not that any should testify of man: for he knew what was in man.
Jesus, the Son of God, knows all about human nature. He was well aware of the truth of Jeremiah 17:9, which states, “The heart is deceitful above all things, and desperately wicked: who can know it?” Jesus was discerning and he knew that the faith of some would-be followers was superficial. Some of the same people claiming to believe when it is exciting and everyone else believes the same way. But keep your faith firm even when it isn’t popular to follow Christ. – Study Bible KJV