Though it is admirable to be committed to what we believe is truth, it's not enough. We must be just as committed to pursuing truth and throwing away those beliefs which have been exposed as lies. To do anything less, is to live a life with some degree of self-delusion.
PR 14:12 There is a way that seems right to a man,
but in the end it leads to death.
Truth that cannot be tested and tried, is no truth at all. If we are unwilling or unable to test it, how can we be sure that what we believe is really true. Are we afraid that it won't stand up to the scrutiny?
Jesus, who is the way, the TRUTH,and the life, sent His Spirit to guide us into all truth.
John 16:13 But when he, the Spirit of truth, comes, he will guide you into all truth. He will not speak on his own; he will speak only what he hears, and he will tell you what is yet to come.  He will bring glory to me by taking from what is mine and making it known to you.
It is the Spirit that reveals the mysteries of God. He reveals the truth about who we really are, and the glorious inheritance God has given to those who have accepted His grace. It is through the Spirit that we KNOW God--the unsearchable One.
"No eye has seen,
no ear has heard,
no mind has conceived
what God has prepared for those who love him" --
1CO 2:10 but God has revealed it to us by his Spirit.
The Spirit searches all things, even the deep things of God.  For who among men knows the thoughts of a man except the man's spirit within him? In the same way no one knows the thoughts of God except the Spirit of God.  We have not received the spirit of the world but the Spirit who is from God, that we may understand what God has freely given us.
We can question what we've known or thought to be truth, with the assurance that we will find truth--if we earnestly search. God promises that those who seek, will find. But the question we should ask ourselves is this: Are we sincerely searching for truth as one would search for a great treasure or are we only looking to validate what we already believe? May His Spirit reveal the answer.