The first thing one ought to do in a genuine search for truth is to recognize that religion is not simply a matter of personal preference. Religion has a tremendous stake in it that is directly connected with the meaning of man’s existence as a whole. To assume that man can determine the meaning of his own existence is to assume atheism. Thus, the search for truth requires an openness to truth and faculties of reason. One can use reason to come to ascertain truth. All we need is to seek it with an open heart. Ask yourself why you are an atheist. If it is a matter of personal preference, then you are surely putting a lot at stake. If you have a more rational reason for it, evaluate it and ask yourself why you hold your belief (just as any Christian should). Faith is not isolated from reason. Rather, it is an extension of it. Thus, we have a duty to pursue truth by reason. C.S. Lewis’s “Mere Christianity” uses reason to bring anyone from atheism to Christianity with the help of using reason and its conclusions (one especially being the existence of the moral law). Religion is not a matter of personal preference, just as truth is. The moment we affirm one person’s behavior over another’s, one religion’s validity over another’s, or point to any sort of moral progress in history, we appeal to the existence of objective truth. Because religions differ and truth is objective, one religion is more or less true than another. Thus we ought to pursue that religion which is most true in accordance with objective truth using the faculties of reason. The same goes for various Christian denominations.
In summary, one isn’t bound necessarily to the religion one is born into firstly because man does not define truth - he discovers it. Therefore some religions and some Christian denominations are more or less true than another. Man ultimately has a duty to pursue truth, which entails the use of reason.