One of the major arguments for the non existence of God is the problem of evil in the world.
If there is a God who is soo loving, Almighty, all knowing, full of mercy and compassion, why is there evil in the universe, why do people hunger and suffer, Why do evil strive over good, Why are the poor and weak marginalised? etc. If God really exists and He knows all, why does He not prevent evils that befalls His children.
Many argue that evil is a product of man's freewill. After creation, all God created was good and since all he created was good, man's freewill would have centered towards good.
Of all God created, it was only man He created in His own image and likeness and this differentiates man from other creatures. God gave man Freewill which is an exclusive characteristics of man.
Evil is a product of man because God gave man freewill. Freewill makes man human. If God had not given man freewill, man would have been placed on the same level with robots. So evil came into the world due to man's abuse of freewill.
Death is inevitable and suffering is part of humanity. Death and suffering are not signs God's non existence because our existence is a participation in the life of Christ of which hardship is inclusive.
The freewill given to man was a responsible freedom and man is culpable for his actions. This explains why after Adam and Evil disobeyed God, they were expelled from the garden of Eden. Man is responsible for his choices.
God placed man in charge of all He created. This makes man a co- creator in the redemptive plans of God actaulised in Jesus Christ.
God exists and HE is all powerful and all knowing and He allows everything to happen for a purpose. Nothing happens out of His knowledge and will and He permits all things to happen.
Evil is a product of man's freewill and man is responsible for his actions. God does not impose His will on man but allows man to live freely.
His ways are not our ways, His thoughts are not our thoughts and His existence does not depend on man's aproval or not.