The word "repentance" comes from the Greek word "metánoia," which literally means “to change one’s mind” to the degree that it results in changed behavior. All Christians fall into sin on occasion. But by the grace of God, we recognize our falling, stumbling, and failures for the sins that they are, and we repent of it, trusting that He who began a good work in us promises that He will complete His perfect work in us one day (Philippians 1:6). Until then, our conduct is but one piece of evidence of our salvation. But where and when our conduct fails—and it most certainly will—then it is our repentance that shows the genuineness of our imperfect but saving faith.