For a moment assume that Descartes' argument works in proving God's existence, does the ultimate conclusion follow as stated in premise 6?

For a moment assume that Descartes’ argument works in proving God’s existence, does the ultimate conclusion follow as stated in premise 6? Can Descartes be certain that God would not allow an evil demon or computer to systematically deceive humanity? Maybe God has a reason, or needs to teach humanity a lesson.

Surname 1Descartes’ arguments on Proving Existence of GodAssuming that Descartes’ arguments in proving God’s existence works, the ultimateconclusion will not follow as stated in premise 9....