Christianity as a religion places great emphasis on proper beliefs. What one believes is essential to being acceptable to God. Believe wrongly and you will be rejected eternally. Mankind is under a commandment to believe correctly, and the church is God's agency to foster this correct belief.
Despite the above, it behooves us all to be a bit humble about our personal concept of reality, which is the sum of what we believe to be true. That's hard to do because our egos tell us that to be wrong about what is true is a serious deficiency, one which marks us as unworthy. Unfortunately, life forces many decisions upon us. Some of these decisions will appear improper in retrospect. Thus to err is essentially human, unavoidably so. Despite this undeniable reality, each of us routinely fall victim to the assumption that what we believe is the absolute measure of truth, what is actually real.
Additionally, we need to recognize that what anyone believes is not based on solid evidence in the vast majority of cases. More often than not, we believe something as true because it is convenient to believe it; it has advantages for us personally. Perhaps, that belief elevates us in our own eyes and possibly that of others we seek to impress. It may have implied economic gain for us. Many, many reasons can be conjured by our minds in making a particular picture of reality appealing.
A great many of our beliefs are seen as advantageous for the simple reason that many others in our society believe similarly. In order to fit in and be a part of the greater whole, we naturally gravitate toward these traditional beliefs. They are familiar and therefore comforting. They allow us to co-exist without drawing attention to ourselves as strange or foolish.
Proving that something is true to another person always requires their willingness to be convinced. That is especially so, if what we intend to prove requires the hearer to change his or her mind about the truth. That inclination to change one's former beliefs will largely depend on that former belief having become unmanageable or no longer completely comfortable.
This is the conundrum of all religions which seek to convert others to their concept of divine truth. People who remain comfortable in their current beliefs are rarely if ever amenable to embracing a new ones, no matter what evidence may be presented. Evidence is never more compelling than the evaluating mind allows it to be.