Perhaps these men believed with their heads instead of with their hearts (Romans 10:10)?

Romans 10:10  For it is with your heart that you believe and are justified, and it is with your mouth that you confess and are saved.

Barclay is very hard on them. He says that “Secret discipleship is a contradiction in terms for, ‘either the secrecy kills the discipleship, or the discipleship kills the secrecy.’” What do you think he means by this? He goes on to say that they feared they would lose so much by confessing Christ and that they had their values very mixed up. “So they lived a lie because they were not big enough to stand up for the truth.”

How often have we not stood up for Jesus because we were more concerned over what other people thought of us than we were of what God thought of us? (John 5:44) In actuality, this is just a form of idolatry (Romans 1:25). Barclay notes that the opinions of men last for only a short time while the opinion of God lasts for all eternity. “It is always better to be right for eternity than to be right for a time.”

John 5:44  How can you believe if you accept praise from one another, yet make no effort to obtain the praise that comes from the only God?

Romans 1:25  They exchanged the truth of God for a lie, and worshipped and served created things rather than the Creator—who is for ever praised. Amen.