The god of christian theism values faith.
"without faith it is impossible to please God, because anyone who comes to him must believe that he exists" - Heb.11
Faith and evidence are inversely proportional - the more evidence there is that god exists the less faith you need in that proposition and vice-versa.
So how can a christian criticise any other faith-based belief? For example they can protest that all the evidence is against the claims of Scientology, but that just means that Scientologists require more faith than christians. Since faith is a virtue, Scientology wins.
Therefore faith as a basis for belief in any specific god is self-defeating.