I also asked MrFreeThinker what the strongest arguments were. Here's his response:
I think (as for a general creator) the cosmological argument (Aquinas' form) is very strong. It is good as it is also supported by cosmological evidence like the expansion of universe that supports the idea that the universe had a beginning. The moral argument is good when talking about a more involved god.
So let's look at these arguments and see if they survive enough scrutiny to show the existence of God beyond a reasonable doubt.
The Cosmological Argument
I hate the summarize the cosmological argument because I think it's well made and nuanced, but many of us may already know it. However, here's the logic of the cosmological argument none the less:
1. Something currently exists.
2. Nothing came from nothing.
3. Therefore the basis of all being must be eternal.
4. This universe is in a state of entropy, had a beginning, and is therefore not eternal nor the source of all existence.
5. So, either the Universe or God is self existent, and since the Universe isn't self-existent, God is, and therefore exists.
The problem with this convoluted argument lies in several layers. The biggest logical fallacy is the false dichotomy between having to choose either God being self-existent or the universe being self-existent. There exists an infinite number of self-existent constructs that could potentially create a universe. God, at the very least must be intelligent by definition, and this argument in no way suggests that the self-existent construct has intelligence.
In other words, the jump from "something is eternal" to "God exists" is a leap of faith with no evidence in this argument to back it up.
Nothing came from nothing also contradicts the premise of a self-existent being. Similarly, quantum physics shows that particles do appear to "come from nothing," but more importantly, effects don't necessarily need a cause. So the entire second premise has been invalidated, making the rest of the argument moot.
The Moral Argument
Here's the basic argument:
1. If we seek to do the highest good through moral law, the result is our own happiness.
2. However, there exists no objective moral law for a being of and by the natural world.
3. Therefore, something outside of the natural world created absolute and objective morals to which we should follow.
1. Some things we can all agree are morally wrong like killing everyone in Canada.
2. Therefore, an objective standard of morality exists and moral relativism is a contradiction.
3. However, there exists no objective moral law for a being of and by the natural world.
4. Therefore, something outside of the natural world created absolute and objective morals to which we should follow.
The question of morality is a deep question. However, like the cosmological argument, a leap of faith is necessary to accept that God exists.
The argument essentially jumps from "objective morality exists," to "therefore a supreme all-knowing intelligent entity exists outside of our universe who created everything and plays a role in human affairs."
I, like many, would argue that empathy is the root of all morality and explains the duality of both objective morality and moral relativism. This is a much simpler argument that explains away all the problems of morality and why morality leads to happiness. Similarly, the morality from empathy argument makes far fewer assumptions than the moral argument for God.
In other words, when Occam's Razor comes into effect, serious doubt is placed upon the moral argument.
Neither the cosmological argument nor the moral argument rely on any kind of empirical evidence. Both are subjective arguments which, while thought provoking, don't show beyond a reasonable doubt that God exists.
More importantly, none of these arguments even address the possibility that the Christian God of the Bible exists, just a deistic god. So not only do these arguments not pass basic scrutiny, they are an even lousier basis for a belief in the biblical God.