Brethren, I do not regard myself as having laid hold of it yet; but one thing I do: forgetting what lies behind and reaching forward to what lies ahead, I press on... Philippians 3:13-14
Another way to discern true Christianity from the false - the effect of shortcomings.
1. The lost religious person. Their shortcomings cause complacency. They excuse themselves with a quaint phrase like "after all, no one is perfect."
2. The true Christian. Their shortcomings have just the opposite effect. Their deficiencies cause him to run even harder.