Believing in God's plan is difficult enough after the cross has revealed Jesus was the promised Son who would crush Satan's head. Imagine what it was like after being cast out of the Garden and not knowing who the "he" of Genesis 3:15 would be.

Even with the promise to Abraham narrowing it down to his family (Genesis 12:3) and then to his son Isaac (Genesis 17:19) the ultimate son was unclear. Century after century, prophecy after prophecy God revealed more and more, and asked people to trust him.

Now the promised salvation has come, but what remains unclear is whether or not you will accept it. That's a decision you have to make.