There are certain things in life that are undeniable.
For example your DNA and your blood type.
If you are of a certain blood type, you may not know the type of blood that you carry, nor that your blood is compatible when mixed with certain people's blood but not others. And you could very well believe that blood type differences are imagined, political, commercial and not in fact real.
That doesn't change the fact that if you receive a blood transfusion from an incompatible blood type you could very well die. So in that sense, your belief would not influence factual outcome upon your body.
So is the same for matters of objective truth - the fact that we are created beings of the one God of Israel who chose Abraham, Isaac, Jacob, David, sent his one begotten son to die for the eternal salvation human beings (who receive that same Jesus Christ and follow him) only to be resurrected again.You can't "believe away" the outcome and consequence of following Jesus or not following Jesus. Belief is... irrelevant to truth.
