The man who never embraces a religion because he can't have a priori assurance that it is the true one, is like the man who never marries because he can't have a priori assurance that this woman is his one true love he was meant to be with forever. Or, he is like a man who keeps his money under his mattress because he can't be sure which investment is the right one. Or, he is like a jury that takes thirty years to decide a verdict, all the while the defendant sits in jail. Or, like the man who stays fat because he can't be certain which diet is the right one.
There may be reasons for not marrying, or for keeping your money under your mattress, or for delaying a verdict, or for not dieting... or for not embracing religion. Not doing so because you can't have objective certainty prior to the decision is a simple misunderstanding of what is at stake.