Found on Christianity Today:
How can we be sure that we are saved? A Calvinist and Lutheran answer.
by Phillip Cary
Anxious about whether he was really saved, North Carolina pastor J. D. Greear kept asking Jesus into his heart—it must have been several thousand times, he says—until he came to put his faith in the truth of the gospel instead. The difference is subtle but fundamental, and Greear does a real service by getting it across clearly in Stop Asking Jesus into Your Heart: How to Know for Sure You Are Saved (B&H Books).
Asking Jesus into your heart by praying some version of the Sinner’s Prayer, in which you acknowledge your sin and need of salvation and then accept Jesus as your Savior, has become something of an evangelical ritual. It can mark the moment of salvation—”the hour I first believed,” as the great hymn says. But like any ritual, we can wonder whether we’ve done it right—whether we were sincere enough and really meant it. At that point it becomes a kind of good work, something we do to get saved. And like every good work, it’s not good enough to assure us of salvation.
Greear is not saying it’s wrong to ask Jesus into your heart. He’s saying it’s not the same thing as believing the gospel. And if we want to be assured of salvation, it’s believing the gospel that actually counts. We are saved by faith alone, not by doing a good enough job praying the Sinner’s Prayer.
The Heart’s Posture
It was reading Martin Luther that brought the difference into focus for him. Greear speaks in very Lutheran terms when he says, “Saving faith looks outside of itself to what Christ has done, not back onto itself at what it has done.” For the gospel is not about us and the decisions we make—not even our decision to choose Christ—but rather about Christ himself, his finished work on the cross and his sitting on the throne of heaven, where he himself is our all-sufficient righteousness before God.
Of course, we do make decisions, and they have their importance. Some people can narrate a specific moment of conversion, and such a moment may have included praying the Sinner’s Prayer. But other people, Greear recognizes, grew up in a Christian home and learned to believe the gospel at such a young age that they cannot remember any decisive “moment of salvation,” and they are none the worse off for that. What matters is believing the gospel of Christ, not remembering when you first believed.
Greear provides a helpful analogy here. He asks us to think of faith as a kind of “heart posture.” Like the physical posture of sitting, it began at a specific moment. But if you want assurance that you really are sitting, do you try to remember when you first sat down, or do you make a point of noticing where you’re resting your weight right now? Well, faith is resting the weight of your soul on Christ and his finished work. It’s not totally irrelevant to remember when you first rested your weight in that posture, but it’s not the most helpful question to ask. Just as you may truly be in a sitting posture without remembering when you first decided to sit down, you may have true faith even if you can’t remember making a decision for Christ.