Anything that begins to exist is not responsible for it's existence.
Natural and artificial objects and events all follow and conform to this law, hurricane, storm, earthquake, reproduction, germination. An earthquake is caused by series of events beneath the surface of the earth, surely it's not the earthquake that causes itself.
Check this out the reason for a rocket's existence is outside of itself, for it took the intelligence, creativity of man and most importantly a material that was subjected to several physical conditions. living entities follows the pattern an offspring is not responsible for it's own existence . A man and woman came together so in actual sense an existing entity cannot have it's own existing explanation. No material object is outside of space and time, and any object limited by these two constrants is forever silenced about it's existence, just like trying to lift yourself by pulling your shoe laces.
May I now say the reason for the existence of the universe is outside of the universe.
We are forced to acknowledge a force, a mind and something personal outside of the universe
God is the reason for the universe, john 1:3
God knows all.
God is outside of space and time.
God caused the big bang aka God created the universe.
God finely tuned the universe to support his creation, us.