“Therefore we also, since we are surrounded by so great a cloud of witnesses, let us lay aside every weight, and the sin which so easily ensnares us, and let us run with endurance the race that is set before us, looking unto Jesus, the author and finisher of our faith, who for the joy that was set before Him endured the cross, despising the shame, and has sat down at the right hand of the throne of God. For consider Him who endured such hostility from sinners against Himself, lest you become weary and discouraged in your souls.” (Heb. 12:1-3)
In the Grecian games, the footrace was first in the order of the events and first in importance. It was deliberately designed as an endurance contest. The race demanded, not brilliant starters, but stouthearted plodders. The word which is translated as “race” (agon) is actually where the athletic contest took place. It is a form of the Greek word agonia which referred to the arena of intense struggle and agony. The point the writer is making to his readers is that Christianity is a marathon, an endurance race for a lifetime.
And since we have a long way to run -- we don't want to be burdened down for the race. That’s why the text continues with “...let us lay aside every weight, and the sin which so easily ensnares us.” This race has eternal consequences, and we don't want anything to get in the way. “Weight” would be anything that would prevent us from going the distance, especially sin! The English Standard Ver- sion words this phrase as “the sin which clings so closely.” Sin deceives us, trips us up, and never wants to let us loose. But the writer says we must cast aside all obstacles if we want to successfully run this marathon.