Romans 4:18-21
Who against hope believed in hope, that he might become the father of many nations; according to that which was spoken, So shall thy seed be.  And being not weak in faith, he considered not his own body now dead, when he was about an hundred years old, neither yet the deadness of Sara’s womb: He staggered not at the promise of God through unbelief; but was strong in faith, giving glory to God; And being fully persuaded that, what he had promised, he was able also to perform.

Abraham trusted beyond anything he could imagine.  He believed God and His promises, not what he could comprehend or make possible on his own.  Abraham and Sarah were both old, past the time of bearing a child.  There was no way for the promise to be fulfilled without the intervention and working of God.  But Abraham knew that if God said it, it would come to pass.  If God wanted something to happen, it would happen, because He would enable it to be so.

It works the same way regarding our salvation.  It seems too good to be true to hope for such a thing.  It is truly beyond what we imagine could be possible.  It’s something we could never bring about on our own.  Sometimes we have a wrong view of ourselves that fails to see our true condition of being dead in our sins and unable to work out our righteousness.  It is a staggering thing so far beyond our own capabilities and what would be possible for us to do.

And so we have no choice, really, but to trust God’s promises and believe His Word.  We have to understand that if something is going to happen, God is going to have to bring it to pass Himself.  And He did so gladly.  He sent His Son into our world.  Jesus went forth to His cross, to His death, to the grave, and He rose again, making our salvation possible.  It was dependent on God coming through and doing everything He said He would do.  And He accomplished that with certainty so that all we have to do is have faith in Him.

We can have great hope when we are hoping in God.  He is a faithful God.  He is a promise keeper.  He is powerful enough and able enough to do those things that seem impossible.  He gave Abraham and Sarah a son when they couldn’t have a child.  He gave us salvation when there was absolutely nothing we could do to bring about forgiveness for our sins.  He gives us His Word so we can know Him and trust Him with a certainty that goes beyond merely wishing for something to happen.  So may we have an unshakeable faith in our great God who can truly do all things.