זוהר שמות — דף קסא ע”ב

The world was not sustained until there arose the will to create man who would engage in Torah; whoever engages in Torah sustains the world. All souls stand before their descent clothed in their form, in a single treasury. The Holy One calls each soul and makes it swear to engage in Torah and to know the secret of faith. Whoever was in this world without seeking to know the Creator, it would have been better for him not to have been created. YHWH is Elohim — this is the principle of all the secret of faith and of all Torah, Written Torah and Oral Torah united as one.