God wills not to save all, even though he “desires” that
all be saved, because there is something else that he wills or desires more, which would be lost if he exerted his sovereign power to save all. This is the solution that I, as Reformed, affirm along with Arminians. In other words, both the Reformed and the Arminians affirm
two wills in God when they ponder deeply over 1 Timothy 2:4 (as we have seen in the case of I. Howard Marshall). Both can say that God wills for all to be saved. And when queried why all are not saved, both
the Reformed and the Arminians answer the same: because God is committed to something even more valuable than saving all.
From the book "Does God Desire All to Be Saved?"