That’s fine, I have Christian friends who are extremely confident that God exist. But:
Suppose a man were to say: ‘I am in love with the most beautiful girl in this country.’ Then they would ask him: ‘Good man, that most beautiful girl in this country with whom you are in love—do you know whether she is from the noble class or the brahmin class or the merchant class or the worker class?’ and he would reply: ‘No.’ Then they would ask him: ‘Good man, that most beautiful girl in this country with whom you are in love—do you know her name and clan?…Whether she is tall or short or of middle height?…Whether she is dark or brown or golden-skinned? …What village or town or city she lives in?’ and he would reply: ‘No.’ And then they would ask him: ‘Good man, do you then love a girl you have never known or seen?’ MN 79
I hope we both agree that to love such girl is rather contradictory affair.
But than, Bhante, you say that you are certain that God doesn’t exist. But what do you mean by “God”?
Is it not the case that first you have to create certain images of God, in your mind, and after that, next step is to say: such God doesn’t exist?
But because you created in your mind certain image of God, in fact at least in this sense your negation turns out to be affirmation of God. Wouldn’t be preferable to keep mind free and void?
But your description or definition of God is your personal one. “God” is merely graphic symbol, here and now visible on my screen, for me it is absolutely meaningless symbol, my mind sees nothing which I could affirm or deny.
But I must be careful saying to my Christian friend: your God isn’t real, it is only certain image, or certain description, which is false, however strong your faith in it is.
I must be careful, since he may answer: well, I have no slightest idea about attributes of my God, apart one description which seems to me valid, namely, God is infinite, you aren’t able to see His beginning, His end, neither you aren’t able to see the change in Him, while he is present.
Here, in fact I think for one who has a respect for Dhamma, name given “God” isn’t important, important is not to contradict Suttas saying that there is no changelles element.