The question should be, what would the world be like without irrational religions. People will always wonder where the universe came from and what happens to us if we die. But too many people want the answers they want to hear, and nobody wants to hear that nobody knows and probably never will. It's all mumbo jumbo for millennia from there.
I find that Jesus knows:
* Without irrational religions the world would be like Revelation 22:2 that there will be healing for earth's nations.
* The universe (material creation) came from God's 'power and strength' (His dynamic energy) according to Isaiah 40:26.
* Jesus teaches what happens at death is that we are in an unconscious sleep-like state at John 11:11-14.
Jesus was well educated in the OT which also teaches sleep in death at Ecclesiastes 9:5; Psalms 115:17; Psalms 146:4.