There are two myths commonly believed among LDS Church members regard infinity and impossible.
God can do anything and he has infinite creations, right?
Yes and no.
God's creations are infinite to us, but they are numbered to him!
God can do anything that's possible and right, but not just anything.
"For behold there are many worlds that has passed away by the word of my power. And there are many that now stand, and innumerable are they unto man; but all things are numbered unto me, for they are mine and I know them." (Moses 1:35).
This likely means that man could not count God's creations during a lifetime, they have a set number still and are not infinite in the true sense, though they will continue to expand forever.
God can do the impossible to us, heal, restore life, etc. However, despite what Mark 9:23 says about all things being possible to God, or he who believes, that verse was not translated correctly.
Joseph Smith's Inspired Version restored that verse in Mark to say that we can do anything God says we can do. Not that God or we can do anything and everything.
God doesn't and can't create something from nothing. He reorganizes existing material; works within his perfect understanding of natural law -- but can't break those laws himself.
God also won't force us to obey his laws or do anything contrary to the Gospel principles.
I don't want to bring God down to our level. He certainly can do things we consider impossible. He's light years advanced of man, but God himself was once a man like we are now and therein lies our hope of slowly advancing, precept by precept to be more like him.