"Nevertheless among the chief rulers also many believed on him; but because of the Pharisees they did not confess him...."
This is a sad, sad situation and a sad state that I'm afraid many folks get in. They come through the church house doors, hear the gospel, believe what they hear, but because they've been told "You'll never get right." or "There's no hope for you." or, such as the case with the above verse, they might be afraid to lose some prestige or standing in their community, workplace, home, etc: they believe, but do not confess. They want salvation, but aren't ready to give up their pride to have it. They hear the trumpet sound, but fail to heed the warning.
As many in my home church congregation has heard me say several times over, if there is one thing in Scripture that flows consistently throughout the pages of our sacred text it is believe, believe, believe. Faith is key, period. Abraham believed and it was counted to him for righteousness; Moses (not the rest of the Israelites) believed and the Red Sea parted; the lame and blind believed and they were made whole. There MUST be belief that Jesus is who the Bible says He is!
But what is that belief without confession? If you truly believed that some catastrophic event was going to happen in your hometown or school or church, would you not share this belief with others? Would you not be blowing the trumpet yourself; maybe demanding the sirens at the local fire hall be sounded? What we believe, we confess. If you confess something that you don't believe, that makes you a liar.
These poor souls in John 12 "...believed on him...", but lacked the confession. So did they truly believe? What confession do you have or lack about Jesus in your own life? Our very lives should be a confession, but the Scripture plainly states, "Whosoever believeth on Him shall not be ashamed." The Scripture also states, "...if thou confess with thy mouth the Lord Jesus, and shalt believe in thine heart that God hath raised him from the dead, thou shalt be saved." Your confession of Jesus will go hand-in-hand with your belief. If your confession is weak, your belief may very well be, too. Why would you not want to tell others of the goodness of God; of the sacrifice of His only begotten son; of the mercy that He offers freely? We should all be fountains overflowing with the Word! "Be ye doers of the word, and not hearers only..."
Jesus said, in John 7:37, "If any man thirst, let him come unto me and drink." PRAISE GOD! Do you not remember that thirst you had before Jesus? Don't you remember that parched feeling and the thought that it'd never be satisfied? If you've drank from His water and He has satisfied that feeling and continues to do so, please pay attention to the verse that directly follows the one previously quoted: "He that believeth on me, as the scripture hath said, out of his belly shall flow rivers of living water." Do you believe the report? If so, get out of your comfort zone and confess it: Jesus Christ came and died to save sinners!