Hebrews 12 applies the examples of chapter 11. Therefore let us also, seeing we are surrounded by so great a cloud of witnesses, lay aside every weight and the sin which so easily entangles us, and let us run with perseverance the race that is set before us, looking to Jesus, the author and perfecter of faith. He endured the cross, despising its shame, and has sat down at the right hand of the throne of God. The readers are told to consider him, so that they don’t grow weary.
Next the writer explains hardship as God’s training. Quoting Proverbs 3, he says the Lord disciplines the one he loves. Human fathers disciplined for a few days as seemed good to them, but God disciplines for our profit, that we may be partakers of his holiness. Verse 11 is honest: All chastening seems for the present to be not joyous but grievous; yet afterward it yields the peaceful fruit of righteousness to those who have been trained by it. The writer urges them to pursue peace and holiness, and warns them not to be like Esau, who sold his birthright for one meal.
The chapter ends by contrasting Sinai and Zion. Sinai was a mountain of blazing fire, darkness and a trumpet, so fearful that even Moses said he was terrified and trembling. Believers have come instead to Mount Zion, to the city of the living God, the heavenly Jerusalem, and to Jesus, the mediator of a new covenant. God promises to shake once more both earth and heaven, so that only what cannot be shaken remains. Since believers receive a kingdom that cannot be shaken, they should have grace to serve God with reverence and awe, for our God is a consuming fire.