"The fear of man brings a snare,
But he who trusts in the Lord will be exalted."
When a person is overly concerned with what others think of him, he is caught in the trap of fear of man. That's just what it is too--a trap. It keeps you in bondage, restricting your thoughts to another person's beliefs. What happens is that you are bringing yourself under someone else's judgement. In effect, you are making them your lord and allowing them to dictate your opinions and actions. Yikes!
It's a dangerous thing to "people please" so why do we do it? We may do so because we don't trust the convictions of our own heart, or we are trying to be "politically correct," or the person in front of us seems so much more convincing than the Scripture we read three months ago. Whatever the case, we put other people's opinions above what we believe the Lord has shown us. We fear them more than we fear God and it's a trap.
If we find ourselves in this situation we might ask ourselves what we are afraid of. Rejection? Ridicule? Confrontation? Physical harm? It could be a lot of different things, but whatever the reason, the solution is to bring ourselves out from under the judgement of people and put ourselves under the judgement of God. We can trust Him because His judgments are just, right and true. David knew this. When the Lord was displeased with David because of the Census he conducted, He gave him the opportunity to pick one of three things as the consequence. David chose the hand of the Lord and said, "please let me fall into the hand of the Lord, for His mercies are very great. But do not let me fall into the hand of man." (1 Chronicles 21:13). David knew that God judges righteously and He is merciful.
Just because someone disagrees with you to your face and their opinion/judgment seems so convincing, (or intimidating) at the time, the judgement/opinion of God is much more real and much more accurate. The fear of the Lord does mean that we tremble at His greatness, in the end it will be the most fearful thing of all, yet if we embrace it now, it brings His goodness. Consider Psalm 33:18-22:
"Behold, the eye of the Lord is on those who fear Him,
On those who hope for His lovingkindness,
To deliver their soul from death and to keep them alive in famine.
Our soul waits for the Lord; He is our help and our shield.
For our heart rejoices in Him, because we trust in His holy name.
Let Your lovingkindness, O Lord, be upon us, according as we have hoped in You."
Matthew 10:28-32; Mark 8:38; Psalm 118:6