Ideas have consequences. Everything anyone does derives from a philosophy, whether they know it or not. And philosophies have consequences. Any philosophy assumes a world view and predicates all actions on the assumptions inherent in that world view.
Fundamentally, there are two world views: 1.) God Exists or 2.) God Doesn't Exist. Each view has enormous implications. There are innumerable variations on each view, and you'd need a philosophy degree to get a handle on them all. I'm dealing with basics here.
If God exists, then he, she, or it, has an identity. God has some kind of personality, from being an amorphous, background force that caused everything to happen and really doesn't care about it anymore, to a personally involved, conscious being that is regularly directing things in his creation and has some very definite ideas about morality and the way things should be done.
If God doesn't exist, then everything that exists is a cosmic accident. There is no directing intelligence that made anything happen. Everything that exists exists simply because it was more able to survive than anything else, and there really is no such thing as morality, judgement, or any given way that things should be done. Survival is pretty much the only thing that is important, and beyond survival, everything in the universe is free to do whatever it can get away with. There really is no such thing as murder, evil, good, bad, or any of that moral stuff. Everything that is just IS, and the Universe, frankly, just doesn't give a damn.
I believe that God exists and the Bible gives the best description of who he is. One of my most fundamental reasons for believing that God exists is the fact that everything, if it evolved, had to evolve according to the laws of physics, mathematics, biology, and whatever other laws of the universe apply to so-called evolutionary processes. Every evolutionary scientist has to base his calculations on those laws. What he fails to consider is, where did those laws come from? If the universe began as absolutely nothing, and everything that happened did so according to those laws, what put those laws in place?
One of the most fundamental laws in logic is that nothing comes from nothing. It is not logically possibly for anything to create itself, because it has to exist before it exists in order to create itself. Sorry, atheists, that just doesn't work. If you start with nothing, you end with nothing. zero times anything is still zero. You absolutely must have something to start with in order for anything to exist.
Then there is the ages-old argument that says if God created everything, what created God? And what created the thing that created God? And what created that thing, and on and on to infinity. This is called an Infinite Regression, and you can find discussions of it on the Internet. The basic problem with an infinite regression is that, if you keep going to a preceding cause, you never reach a cause. When you ask the question "what created God" you are not acknowledging God as a fundamental cause. You are saying that God has another cause for his existence. And that cause has another cause. You are ostensibly taking the argument back to its beginning, but you will never reach a beginning, because you keep repeating the question "what caused this stage of the beginning?" So you end up with an Infinite Regression. You will never reach a cause, and you will never answer the question. Posing an infinite regression is simply a way to avoid the fundamental logical fact that there has to be a first cause.
Science (true science, that is, not evolutionary science) has pretty well proven that there was a Big Bang that began the universe's existence. All the details aren't worked out and there remain lots of questions, but in as much certainty as true science can give us, we know there was a Big Bang of some sort that began the existence of the Universe. So science itself makes it clear that there had to be a beginning.
The next question to ask is "what caused the Big Bang?" Since we have established that nothing comes from nothing, something had to exist before the Big Bang in order for the Big Bang to happen. I say God is the most logical cause for the existence of the Universe.
This is the foundation of my philosophy, and everything I believe and do is based on it.