Turn with me to Matthew 14, and we're going to look at the incident where Peter walked on water. What's remarkable about this account is how strong Peter's faith and his sense of personal assurance seemed when he stepped out of the boat-compared to how quickly he began to sink in despair. That's a great metaphor for faith-at least it reflects how my faith is sometimes easily and unexpectedly assaulted by doubt, just when I thought my assurance was strongest. So let's consider what that passage teaches about strong faith-and weak faith; fearless faith and faltering faith-and we'll draw out some implications related to the assurance of our salvation...