Is It Logical To Have Faith?

Yes, it is.

In the first half of the 20th century, Bertrand Russel and Alfred North Whitehead attempted to compile a comprehensive system of logic and mathematics that would be entirely internally consistent and self-evident. They were miffed by the paradoxes of set theory, and the project was finally put to rest by Kurt Goedel's theorem of incompleteness.

In a nutshell, Goedel demonstrated that no system of logic or mathematics can prove its own axioms. Every logical system relies on a priori acceptance of unprovable first principles.

Life, too, relies on faith. We cannot step out of our beds in the morning without pure, simple faith in hundreds, perhaps thousands of basic assumptions for which we have no real proof. We run our lives with an unquestioning assurance that today will follow the same laws as yesterday and tomorrow the same as today, that our senses are not deluding us, that we are awake and not asleep, that our memories are reliable, that our food is not poisoned and our doctor is not out to kill us, that life is better than death and that all its pain does not measure up to its happiness.

It is logical to have such faith, because otherwise, life would have to be led in an insane asylum or under heavy psychotropics. So, too, it is logical to have faith that G‑d is good and there is only one of Him.