Spiritual dullness, overconfidence, or lack of concentration can likewise cost Christians. Recall how Paul urged the Philippians in 2:12 to never stop working at their salvation. The apostle is saying basically the same thing here in a slightly different way. The Christian who does not concentrate on living the kind of life to which God calls him may, like the overconfident athlete, be eliminated from the race and in the end lose the blessings God has in store for him. A believer’s sanctification