Similar language to John 7:13 occurs in ch.12, except, by this point, some of the leaders have become convinced of Jesus’ identity. Here is v.42 Nevertheless many even of the rulers believed in Him, but because of the Pharisees they were not confessing Him, for fear that they would be put out of the synagogue…The reason being put out of the synagogue was such a serious threat is because that would cut someone off from all religious privileges and the teaching of the Scriptures, all of which are foundational to Judaism.
John gives a heart diagnosis for this fear in the very next verse in John 12:43 for they loved the approval [or glory] of men rather than the approval [or glory] of God. When there is that kind of love, the fear of man, which is actually a fear of what man can do to our reputation or livelihood or comfort or relationships, can gain a tremendous stronghold in our lives. It can affect all of our relationships and decision-making and muddy the waters as it relates to a pure devotion to Christ.
The Apostle Paul knew that the fear of God or pleasing God could easily be snuffed out by the fear of man or pleasing man. This is why he wrote in Gal. 1:10 For am I now seeking the favor of men, or of God? Or am I striving to please men? If I were still trying to please men, I would not be a bond-servant of Christ. Paul is essentially declaring: “I can’t be a slave of Christ if I’m enslaved to pleasing man.” Reason being, that enslavement creates a line which we determine cannot be crossed for the sake of our protection, even if Christ requires that line be crossed in order to obey him.
Thus, when fear of man is present, our flesh deceives us into thinking it’s better to displease Christ than displease another person. Accordingly, the crowd in John 7 and the blind man’s parents in John 9 and the religious rulers in John 12 have no problem keeping quiet about Christ, as long as the Jewish leaders are not displeased with them. They have determined that would be more detrimental than refusing to publicly swear allegiance to Christ. That’s because fear of man prevents devotion to Christ since that heart is mainly devoted to protecting and promoting oneself. In that case, the cost of following Christ is just too costly, so it’s best to play it safe in order to protect our well-being. Clearly, God does not pour out the grace of discernment on those who are pridefully self-protecting (James 4:6).