Great Quote: C.S. Lewis on God and Impossibilities

God's omnipotence means [His] power to do all that is not
intrinsically impossible. You may attribute miracles to Him,
but not nonsense. This is no limit to His power. If you choose
to say, "God can give a creature free will and at the same time
withhold free will from it," you have not succeeded in saying
anything about God: meaningless combinations of words do not
suddenly acquire meaning simply because we prefix to them the
two other words "God can." It remains true that all things are
possible with God: the intrinsic impossibilities are not things
but nonentities. It is no more possible for God than for the
weakest of His creatures to carry out both of two mutually
exclusive alternatives--not because His power meets an
obstacle, but because nonsense remains nonsense even when we
talk it about God.
   ... C. S. Lewis (1898-1963), The Problem of Pain