The time has come to reveal my cards. Not only are my politics tilted towards the left wing, I'm also a religious person, even if I don't obey all of the Mitzvot (I hope that the ones I'm missing are the ones between me and god, but I'm not entirely sure).
So if I believe in god why do I also believe in the Big Bang and modern geology, and Evolution and so on? Only because I think that the theories of modern science are doing a pretty good job of explaining the world around us. I would try, with my very humble abilities to explain why and how, but many authors, far better than myself have already done so. The photos at the end of the post mention two very good books about these subjects.
So if I believe in god, why do I also believe in the big bang? simply because I think that the Big Bang proves god's existence. After all, if the constants for creating the universe were even very slightly different, there would be no atoms in it, much less planets or life. I think it a proof of god's existence that he (or she) managed to create such a wonderful universe based on such a small number of particles and principles.
What does all of this have to do with left wing politics? Very simple. If any left wing ideology does not insist on the fruits of modern science, it has given almost all of the ground right there. There is no way of convincing anyone of doing something 'against nature', if there aren't very powerful arguments at the other end of the scale...
Note: the video above is of Amnon Yitzchak, a Jewish religious person who clearly does not believe in the Big bang, Evolution and the rest of the lot, kudos for anyone who tells me of Christians using similar lines of reasoning and rhetoric.