If you don't allow a definition of "God," then the conversation is a waste of time, just as any philosophy is a waste of time if one of the participants refuses a definition.
My view is that there might be "superman" types out there in space, who can work wonders and who would seem gods to us -- not unlike the Greek pantheon, but they are not "God."
I also think there might be a force or presence in the universe that makes sentience and so on possible, but forces and presences are not God either. This is just avoiding admitting that you don't really believe in God either. Some honesty in the discussion is necessary.
The deity in question does not have to be the Abrahamic God -- heaven help us if he is as this God seems rather evil -- he could be Brahma or Zeus as many of the ancient philosophers perceived him -- the key is the word "omnipotent." The thing is if he is not omnipotent he is not God, but superman, if he is God he is irrational because omnipotence, as even the Scholastics understood, leads to self-referential logical contradictions -- otherwise known as reductio ad absurdum proofs that the premise is false.
Now the "standard" resolution offered for this is the assertion that God is omnipotent -- he can do anything -- except things which he cannot do. The problem with this is that this limitation applies to every motivated being. Indeed, I am omnipotent if you allow such an exception -- I can do anything except what I cannot do.
This is what is behind the assertion that God is irrational. There is also the clear evidence we live on an earth where life is dominated by the principle of natural selection, and natural selection implies constant fear and suffering and disease and death. To me this is the "problem of suffering" and rules out any deity with good intentions. A de fiat creation would have been kinder than God using this method to create life.
It is fairly obvious to me that these arguments are not understood by some of the participants here, since the responses are not to the point. All I can say is that if you don't understand the arguments about God, you have no business having opinions on the subject.
Regarding Buddhism, the Buddha was (if he existed historically) pretty much an atheist in the sense that he did not think there was a god, but he didn't care much -- he said our problems are the same as those of the gods if they exist -- the problems of existence and karma and suffering -- so gods are not relevant. As Buddhism evolved it accepted existing rituals and deities of the areas it entered, as part of its generalized notion of tolerance that goes beyond just getting along but includes allowing "worship" of extraneous deities in temple by those so inclined and the withholding of criticism or question by the monks, who are trained better, of what those untrained may do. I think this historical practice has been wise, but it does have its problems.
It is easy for a relatively intelligent person who has not undergone indoctrination to see that all "faith" (not just religious faith) is mistaken and generally wrong and often harmful. One can have opinions if they are based on valid and repeated experience, even opinions that approach belief, but never should one allow actual belief, where one has made an emotional commitment to something.
Religions make a virtue of faith, but this is seriously wrong. It is in fact a vice -- an easy way to excuse believing things one would like to believe even though there is insufficient evidence. One should only have opinions (where one can readily change one's mind without experiencing guilt or fear) when the evidence warrants it.
All that said, I do not oppose religion completely. Many of the things religions do are good. The present Pope, for example (as opposed to some of his unfortunate predecessors) seems to have a relatively open mind and is a preacher of love and tolerance and downplays doctrine. The same can be said of the Dalai Lama. Many Muslim clerics preach the same message, although unfortunately it seems most do not and many are sources of hate and intolerance. Any religion that teaches that it alone is true is likely to be this way -- in fact such a teaching makes a religion more a force for harm than for good.
It can also be argued that he was mentally disturbed in certain ways. We do not criminally punish the insane.
I am an atheist, so don't have the problem of a god dispensing justice and weighing our soul and if it is just a little too evil we go to Hell otherwise we go to Heaven (and the vast majority of people no doubt are very much on the edge).
I do, however, think we have an afterlife, or at least suspect it, given considerations of the likelihood of our being in an illusionary world rather than a real one, and when we die we go up a level to greater reality. This is a probabilistic argument recently expressed in some popular movies (where it is called virtual reality), rather stupid ones, but it seems probable, and would present a chance for what Asians call karma to do its thing -- when you do harmful things you make yourself slightly more evil, and vice versa, and this gets reflected in the more real existence to come. There is no judgment involved -- it is all rather automatic or even mechanical, and came into existence through people like us (but more advanced and probably better and smarter) creating sub-realities. Maybe it has always existed.