first of all, i am not afraid to admit my religious thinking is influenced by islamic beliefs. but secondly, i have studied gist of all the world religions. thinking of god is perhaps one of man's most primitive acts.
----on one hand....
god exists; when i want to convince someone as a member of proselytising religion; my point would be; this universe may be an accident; the whole idea of life would be accident; but the very fact that as human beings; we are able to think about the supreme being, creator of everything, and in essence accept his supreme powers, and submit to his will, is, in fact a convincing start. it can't be a mere coincidental fabrication in every known culture and civilisation in history of mankind, that idea of god has evolved and persisted, essentially in the same central form. even polytheistic religions have an idea of one supreme god above all others.
other argument, which is not entirely convincing to me is, of final justice for man. given life is so unfair to literally all those who have lived; there must be a final and fair justice. religions having idea of afterlife would preach this argument; as all of them believe in concept of heaven and hell; in fact quran says in chapter zilzaal ' whoso does good an atom's weight will see it then (judgement day), and whoso does ill an atom's weight will see it'. that essentially encompasses this argument.
and finally among many verses in quran; one verse that overweighs all arguments is about creation of the universe. in chapter anbiyaa, it is said 'have not those who disbelieve known that the heavens and the earth were of one piece, then we parted them, and we made every living thing of water?'. first part refers to the big bang theory, actually i didn't use 'alludes' because the words don't seem to allude, they refer, too clearly and directly to big bang. and second part is self explanatory; to just add; not a single living organism has been found of which water is not a constituent.
----and on the other.....
god does not exist; atheists like bertrand russells and richard dawkins of every age made their names for their anger towards believers of god. without filling up pages with their arguments; i can summarise their whole philosophy in a few words- 'unceasing human sufferings and sorrows- natural or social, is a proof enough that a merficul god must not exist'. russell says in one of his articles that one should go to the children’s ward in a hospital and see how merciful believers’ god is. while dawkin generally gets odd with human sufferings caused by belief in god; and hence he professes, god must not exist, else we won't have such un-ideal and imperfect world, as we know it; marred with wars, corrupt beliefs and sometimes hateful ideology.
regarding the argument of final justice of believers; atheists have got their own argument. russell asks; if you see rotten oranges in top layer of a box full of oranges, then there is a higher probability that whole box would have rotten oranges; than the opposite. sounds intelligent; but a bit verbose to me.
when i have my moments of doubt; the question which disturbs me most is; if god created us from nothing; why should he punish us in this life or afterlife if we fail to follow his command. why the experiment of creating; testing; punishing- for which we as humans, unfortunately don't seem ‘originally’ responsible; should convince a rational mind that it is an act of mercy in any way?