Hebrews 12.18-24:
For you have not come to what may be touched, a blazing fire and darkness and gloom and a tempest (19) and the sound of a trumpet and a voice whose words made the hearers beg that no further messages be spoken to them. (20) For they could not endure the order that was given, “If even a beast touches the mountain, it shall be stoned.” (21) Indeed, so terrifying was the sight that Moses said, “I tremble with fear.” (22) But you have come to Mount Zion and to the city of the living God, the heavenly Jerusalem, and to innumerable angels in festal gathering, (23) and to the assembly of the firstborn who are enrolled in heaven, and to God, the judge of all, and to the spirits of the righteous made perfect, (24) and to Jesus, the mediator of a new covenant, and to the sprinkled blood that speaks a better word than the blood of Abel. (ESV)
Discipline, training, and endurance will bring us to the end of the race. And the end of the race is confirmed to us in the above verses to be Mount Zion, which is the heavenly Jerusalem. Certainly we must exercise our will and volition to see this race to the end, but God is the One who gives us the ability and strength to actually compete in the race. And it is understood that we are not competing in a literal sense with other people. But rather, the picture of running in a race indicates that we must live devoted to God with the intensity and seriousness that a race would demand of us.
Mount Zion and Jerusalem are the same place. It is the City of David, as it is designated in 2 Samuel 5.7. And Mount Zion is the place geographically where God has chosen for His King to reign, as set forth in Psalm 2.6. Mount Zion is the place of the Temple Mount and it is all within the ancient, expanded perimeter walls of the City of Jerusalem. I believe that Jesus will rule at the end of the age literally on the geographic place of Mount Zion. But the ultimate fulfillment of Jesus reigning forever as King on Mount Zion is Jesus reigning in heaven, in the heavenly City of Jerusalem at the right hand of God the Father.