A paraphrase of Puritan pastor Thomas Brooks, regarding a person believing himself righteous based on being less sinful than the person next to him: When you are in Hell, suffering God's wrath for all eternity, will it comfort you to know that you are better than the person next to you? Gotta love those straight-shootin' Puritans.
There was apparently a time when people who worked on large wheat farms were taught to escape a sudden oncoming bush fire this way: they were to burn the area around them, stamp out the fire, and try to get down into the dirt as much as possible. This way the fire would go around and over them but would have no fuel where they were laying, leaving them unharmed once it passed. In the same way, we cling to the cross of Christ because it is the only place where God's wrath has already been poured out and spent. When the day of judgment comes and God's wrath falls, we will be safe in Christ.