Well, although it is said - and rightly - that God wills the salvation of all and that no man can be called to do the impossible, it is true that God elects certain men to salvation, while He allows others to fall away and sin. He provides one with the grace to be sanctified and glorified while permitting another to sin. So therefore it should be said that God does not will equally the salvation of all, or He would accomplish this, His will can not be frustrated. It may appear arbitrary that God elects Bob to eternal life while allowing Robert to sin and die impenitent, but it is a mystery unknown to us in this life.
As regarding free will, it is God Who acts in us for us to will and to accomplish, He has mercy on whom He has mercy. Without grace man can do nothing truly good.
He could have freely and without injustice, allowed all men to perish. Who are we to reply against God?
For Thomists and Augustinians, when God out of mercy/love elects one individual to salvation, He accomplishes this infallibly by bringing the free will of man to Himself. So it is not merely God supplying sufficient grace, which man accepts in the sense of the presentation of a contract to sign. Again, this is another mystery.
This is much more complicated than God willing men simply to accept Him, with Him looking on as an eager spectator.
