Why do you believe that your faith's teachings provide the best answer to the meaning of life?
I feel a bit uncomfortable with the phrase "the best answer" as this implies that our different faiths are mutually exclusive (there can only be one that is best). I don't believe that. Perhaps "best" means the best for you at a particular time in your spiritual development.
As for answers, Buddhism does not supply an answer to all the questions about life. For instance we don't have a genesis story. Rather, it stresses the importance of asking a good question. From a good question there is the possibility of inquiry and from sincere inquiry there is the possibility of authentic insight. Insight is an answer from the heart and is deeper than an opinion or belief. This kind of answer is the best answer in that it strikes us deeply and comes from our own efforts. The teaching guides us in this inquiry.
The Buddha's question to his followers was and continues to be, "What is the cause of your suffering?" It is a very personal question that requires sincere and determined self-inquiry. In our texts the Buddha speaks to this basic question, time and again. Once the basic needs of life are met, he suggests, the problem of suffering rests in our own hearts. When someone would go off topic and ask him who had the best teaching he would bring them back and say that's not important. "Why do you suffer?"
So, a good question can lead to a good answer. From his own enlightenment the Buddha offered answers that now form the basis of Buddhist faith. But faith and belief are not enough. In an odd sort of way, faith in the Buddha's question is the faith to doubt. A great Zen master put it this way, "Little doubt, little awakening. Great doubt, great awakening. No doubt, no awakening."