Here goeth me, thinking out loud. Yes, it is God's will that all be saved- But when you look at this verse in the context of the rest of God's Word, it is not God's will that all be saved at the expense of His justice. It is God's will, in short that all meet the perimeters to be saved. If they don't meet the perimeters than He will not save them, even though it may have been God's own desire that they meet those perimeters so that He could justly save them. If an individual refuses to meet those perimeters, then our own prayers can't save them.

Hmm. Tear it apart. I am thinking out loud.