In Romans 8:31-32 Paul wrote, "What, then, shall we say in response to this? If God is for us, who can be against us? He who did not spare his own Son, but gave him up for us all—how will he not also, along with him, graciously give us all things?"
For those who have trusted the Lord Jesus as their Savior, this verse gives us solid confidence that the Father will always be for us and never against us. The logic of this verse is that if someone can do the hard thing, we know that he will be able to do the easy thing. If God was willing to do the hardest thing imaginable for Him--delivering His Son to the cross--then we know that He will be able to do the easy thing--freely giving us all things that we need.
I recently preached a message on this passage at our church. Here is a portion of that message and a weightlifting illustration we used to drive home the point.
But if you want to listen to what is perhaps the greatest sermon on this passage ever preached, listen to John Piper's sermon God Did Not Spare His Own Son. My wife and I happened to be in the audience that Sunday.