Philosophy and Proofs
Atheism includes any philosophy which claims that no God or gods exist, including any rational or reasoning creator of the universe.
Christianity is the philosophy that claims that Jesus of Nazareth is the Son of God and Jewish Messiah (or Christ); that he was crucified, died and was buried, and rose again three days later; that his death was an atoning sacrifice for the sins of his followers; and that placing one's trust in Jesus is how any sinful person can be forgiven and made righteous before their creator.
Empiricism describes any philosophy which claims that all knowledge originates in experience, denying the validity of both deductive reasoning and divine revelation.
Islam refers to the specific philosophy of the Muslims, a monotheistic and unitarian belief system declared by Muhammad in 610 AD and described in the book known as the Qur'an.
Monotheism refers to any philosophy which claims that there is only one supreme creator of the universe.
Open theism refers to any philosophy which claims that there is a supreme creator of the universe who does not foreknow the outcome of human choices.
Pantheism denotes any philosophy which claims that god and the universe are identical.
Polytheism refers to any philosophy which claims that there are multiple supreme creators of the universe.
Rationalism describes any philosophy that claims that beliefs and opinions should always be logical, deductive conclusions rather than being based on experience, observations, religious teachings, or divine revelation.
Theism includes any philosophy which claims that some kind of God or gods exist.
Trinitarianism is the philosophy that there is only one God in terms of essence or being; and that the one God is revealed through three eternally distinct persons, specifically, the Father, the Son (Jesus of Nazareth), and the Holy Spirit. Trinitarianism is unique to Christianity.
Unitarianism refers to any philosophy which claims that divine sovereignty is not shared in any way.
In Printed Form
Along with numerous other authors including Don Landis, Bodie Hodge and Roger Patterson, Timothy McCabe contributes analyses of various world religions and cults in this volume from Master Books.
"How is God any different than Santa Claus?"
This is sort of an odd question as there are so many very obvious differences. For example, Santa wears a red hat, whereas God doesn't have a physical head to put a hat onto. I don't know of any religion or worldview that claims that God climbs in and out of chimneys, either. There is, in this question, an implicit attack on theism. However, it is quite possibly one of the silliest attacks on theism I have ever encountered, and I encounter it rather frequently.
"Your god, in his own holy book, admits to having created evil (Isaiah 45:7). Why then should I worship him?"
In Isaiah 45:7, the KJV translates the Hebrew word "rah" as "evil". More modern English translations often opt for the word "calamity" instead. Either one of these translations is viable and could be the intended meaning of the passage. However, that God is ultimately the Uncaused First Cause of all sinful actions is clear from both scripture and reason, so even if the verse cited does not make the point, the general concept behind the question remains.
"Is what is morally good commanded by God because it is morally good, or is it morally good because it is commanded by God?"
This question has been around at least since Plato, and is known by the name of the "Euthyphro Dilemma". It's really nothing more than a silly trick question wearing a "deep" philosophical mask. If one were to go with the first option provided, it leads to the conclusion that God is subject to the authority of Objective Morality and is not actually able to do whatever He wants, making Him not really God.