Jesus is the author and finisher of the faith. 12:1-4.

After explaining examples of the heroes of faith, the author exhorts the readers to fix their eyes upon Jesus, the supreme example of faith. He wanted to motivate the future generation to run the race of faith. Christian life is a race and it must be run with patience looking unto Jesus. Heroes of faith testify to the power of faith and we must follow their example. They set an example of what it looks like to truly live by faith, not by sight ( 2 Corinthians 5:7). Christ is the beginning and the end of Christian life. He is the pioneer and the finisher of our faith.  Consider the example of Christ who willingly endured the cross despising the shame of death because of the joy of becoming the redeemer of the world. Christ's example would motivate us to lay aside every form of sin that hinders our spiritual progress. Consider, how much greater was Christ's suffering than ours and the eternal blessings of it. The writer reminds the readers that though they suffered scorn and opposition, they have not suffered death. So let us run the race set before us by looking to Jesus who is seated at the right hand of the throne of God in heaven. As we set our eyes on the Christ who gave his life for us, he will give us strength to run the race set before us with endurance.
Do not despise the disciplining of the Lord. 12:5-12.
From verses 5 to 12, the writer encourages the readers to regard their suffering as fatherly discipline of God. Here the author quotes proverbs 3:11-12. This suffering is actually a growth process in their spiritual life. Suffering is not always the proof of sin. Though Christ was sinless, He learned obedience through suffering and became the author of eternal life (5:8, 9). The discipline of these readers is compared with the suffering of Christ. God's children are disciplined to correct them and for their good. Believers who sin and never be chastened are not actually saved. God disciplines us so that we might share in His holiness. The chastening is a training process to get in shape spiritually. Chastening gives assurance of God's love towards us. No discipline is joyous for a while but afterward it will yield peaceable fruit of righteousness.

Without holiness no one will see the Lord. 12:13-17.
The readers are encouraged to stand firm on their shaky legs so that they may not become spiritually disabled. They should pursue a straight path, so that they may not be dislocated and get worse. When few believers slip away from faith, it is easier for many to fall. So encourage each other and live in harmony. Christians must try to live in peace with everyone. Also they should live a consecrated and holy life. Without holiness no one will see God.  God wants us to live a sanctified life. Practical sanctification is essential for growing into the likeness of Christ   (1 Thessalonians 5:23). Love is the highest expression of practical sanctification and righteousness. It is an ongoing work of the Holy Spirit, aligning our hearts with God's heart. Thus  we are prepared for God's work. The writer warns of the danger of apostasy. Apostates would not receive the blessings of the grace of God. Apostates are the defectors from the truth though they profess to be Christians. They are like poisonous roots that corrupt many by their doubts and denials. It can lead to immorality and ungodliness (2 Peter 2:1). Esau is an example of it. He traded his birthright for a single meal. Afterward when he wanted to inherit the blessing, he was rejected. It was too late for Isaac to change his mind or reverse the blessing. Those who willingly renounce Christ for worldly gains and pleasure cannot be renewed to repentance. A classic example is Judas Iscariot who was with Christ for more than three years. How sad that he was so close to Jesus yet lost. It is the solemn warning against apostates.

The blessings of the new covenant. 12:18-24. 
In verses 18 to 24, a comparison is drawn between old covenant and new covenant. Here the writer warns the danger of obeying the old covenant and rejecting the new covenant which Christ established.  The old covenant was intimidating. Like the rest of the warning, the purpose of this warning is to prevent the readers from turning away from Christ and His blessing.  The scene of Mount Sinai was one of darkness and fear.  Men and animals faced death even by touching the mount where God stood (Exodus 19:12, 13). Moses said about this place that "I am terrified and trembling" (12:21). But under the new covenant, we come to a figurative mount Zion, which is the city of the living God, the heavenly Jerusalem. Those who believe in Christ have access to this place under the new covenant. They will enjoy its fullest blessing when the Lord returns.

The promise of an unshakable kingdom. 12:25-29. 
Those who believe in Christ have already entered into the New Covenant and the spiritual Kingdom of God. Figuratively angels minister there. This is the place of the general assembly and where the church of the firstborn is assembled. There we see God, the judge of all people. Here believers are made perfect by Jesus the mediator of the new covenant. His sprinkled blood speaks of cleansing and pardon, unlike the blood of Abel which cries out for vengeance. Those who disobeyed God under the old covenant have perished. Then, how much more is the punishment of those who reject Christ? Now God speaks from heaven through Christ. When God spoke, it shook the earth and heaven (Exodus 19:18). God will shake the earth and heaven again (Haggai 2:6). Probably this is going to happen at the return of Christ. All things are temporal and will be destroyed. Only the spiritual and heavenly things will remain. Believers will inherit a kingdom that cannot be destroyed.  Christ will establish His literal unshakable Kingdom. So let us be thankful and please God by worshiping Him with reverence. The writer closes the chapter with a warning. “Our God is a consuming fire"(Deuteronomy 4:24).  So we should live a life of devotion to Christ.  Christ's grace is not cheap. He gave his life to save us.  We are saved to live in the newness of life in Christ.  This is the privilege and responsibility of every born again Christian.