John 12:42-43

Yet at the same time many even among the leaders believed in him. But because of the Pharisees they would not confess their faith for fear they would be put out of the synagogue; for they loved praise from men more than praise from God.

many even among the leaders believed in him
John 12:11 ... for on account of him many of the Jews were going over to Jesus and putting their faith in him.
John 7:47-49 "You mean he has deceived you also?" the Pharisees retorted. "Has any of the rulers or of the Pharisees believed in him? No! But this mob that knows nothing of the law--there is a curse on them."

But because of the Pharisees
John 7:13 But no one would say anything publicly about him for fear of the Jews*.

for fear they would be put out of the synagogue
John 9:22 His parents said this because they were afraid of the Jews*, for already the Jews* had decided that anyone who acknowledged that Jesus was the Christ would be put out of the synagogue. (a social ostracism as well as religious)

for they loved praise from men
1 Samuel 15:30 Saul replied, "I have sinned. But please honor me before the elders of my people and before Israel; come back with me, so that I may worship the LORD your God."

more than praise from God
Romans 2:28-29 A man is not a Jew if he is only one outwardly, nor is circumcision merely outward and physical. No, a man is a Jew if he is one inwardly; and circumcision is circumcision of the heart, by the Spirit, not by the written code. Such a man's praise is not from men, but from God.

NOTES:
* Jews - in these instances are Jewish leaders hostile to Jesus
1 Samuel 15 - the context of Saul's failure
Read Romans 8

(parentheses are mine)

Scriptures taken from the Holy Bible, New International Version® NIV®, Copyright© 1973, 1978, 1984 by International Bible Society. Used by permission. All rights reserved worldwide.