Ultimately your "faith" must incorporate the entire universe.
As an atheist, ultimately you believe that the entire universe had no beginning, that matter and energy are eternal, and that this mindless matter and energy at one point in time just happened to fall together under the right circumstances and sentient beings were produced.
Atheists must face the existence that their "faith" mandates. An existence where there is no ultimate purpose to his/her existence. An existence in which they are dead and buried in but a spec of time in relation to the cosmos. An existence in which nothing they do will ultimately matter at all.
Atheists must face the fact that their faith precludes any such thing as absolute morality. That morality, in all its forms, is simply man-made and has no ultimate bearing on anything. You can be a Hitler or a Stalin and it will not matter. You can be a Ted Bundy, a Pol Pot, a southern slave owner, or a mad priest during the Spanish Inquisition. You can abuse a little boy or girl, rape, pillage, steal, maim, torture, and kill all you want with no ultimate consequences because nothing is really right or wrong. All morals are man-made concepts and mean nothing and the picking and chosing of which morals you will adhere to is, at its base, a useless and empty exercise that signifies nothing.