Existance of god
Everything must have a cause. It is impossible to continue backwards to infinity with causes, therefore there must have been a first cause which was not conditioned by any other cause. That cause must be God.
Objections: If you allow one thing to exist without cause, you contradict your own premise. And if you do, there is no reason why the universe should not be the one thing that exists or originates without cause.
Animals, plants and planets show clear signs of being designed for specific ends, therefore there must have been a designer.
A very large number of people claim to have personal religious experiences of God.
Objections: We cannot assume that everything imagined in mental experiences (which include dreams, hallucinations etc) actually exists. Such experiences cannot be repeated, tested or publicly verified. Mystical and other personal experiences can be explained by other causes.