“Theodoret, a Syrian bishop in the fifth century, likened the gospel to a pepper: “A pepper outwardly seems to be cold…but the person who crunches it between the teeth experiences the sensation of burning fire.” In the same way, he goes on, the gospel can appear at first like an interesting theory or philosophy. But if we take it in personally we find it full of power.
What does its power do? It is the power of God “unto salvation” (Romans 1:16, KJV). The gospel’s power is seen in its ability to completely change minds, hearts, life orientation, our understanding of everything that happens, the way people relate to one another, and so on. Most of all, it is powerful because it does what no other power on earth can do: it can save us, reconcile us to God, and guarantee us a place in the kingdom of God forever.”
(Timothy Keller, Romans 1-7 For You, p 20)