Sometimes it may seem to us that God's plan is ridiculous, even laughable. That's how it seemed to Sarah when God announced that she would be having a son in about a year's time. However, what was thought to be ridiculous was actually a miraculous way in which God kept his word and brought blessing to the whole world.
Similarly, the gospel may seem ridiculous to us. The idea that God incarnate would die for our sins, then rise again on the third day to give us his righteousness sounds laughable. But it is miraculous, and this ridiculous plan is our only hope.