You have to stand firm in the face of a total lack of evidence
Faith in God is not based on a total lack of evidence. On the other hand, it is based on a whole bunch of evidence, although none of this can really be proven. Sorta like evolution, lotsa things point to it, but no one can go back and time and witness it happening. Therefore, people have reason to doubt it happened. In the like manner, people doubt that God exists. But not because there is not evidence, but because they choose not to believe.