There are propositions that were used by the philosophers to prove the existence of God. For me, the strongest argument are cosmological and teleological argument.
I can hardly believe that the world or universe existed by chance. In our lesson in Space and Time, we discussed that before the universe existed, there is an empty space and time. Is it possible that the empty space and time has something to do with the creation of the universe? But how come that the universe just began or existed from nothing or from an empty space and empty time? I am doubtful that it will exist from an empty space and time. There must be an intelligent and necessary being that created the universe before it exists. If we apply the principle of causality that everything has a cause, the universe must have a cause and it is God.
We can apply the cosmological argument that God is the ultimate reason or cause not having or needing something for Him to exist. But if the principle of causality is true, there is an infinite regress of causes which is not enough in proving and stating that God did not need something for Him to exist because if the universe was caused by God, then God was also caused by something. The strong point of cosmological argument is that it is incredible that the universe should just have happened. How can we say that it is God who created the universe? If it is not God, who created it?
The teleological argument or argument from design convinced me that God exists because the universe has a creator or designer. The different kinds of systems in our body are amazing that I can hardly believe that it is just happened and no one created or designed it. The arrangement of the universe seems to need an intelligent mind to explain it. It is really doubtful that the world existed only as a result of a chance of combinations of atoms. Is it only a matter of coincidence? If it is not, then there is someone who created it it and it is God.