I do all things for the sake of the Gospel, so that I may become a fellow partaker of it.  1 Corinthians 9:23 NASB

We as believers then simply, though not easily, must not let go of the Gospel. If we continue holding fast to “the faith,” we can rest assured that Christ is ours and we are His. That doesn’t mean we won’t sin, take a detour or wrong turn, or even that our faith is perfect and we never struggle with doubt. But seasons of struggling and having imperfect faith is set in contrast to willful unrepentance and rejection of Christ’s Gospel.

Only those who repent of their sins - seek God, welcome Holy Spirit, trust Jesus - persevere for His kingdom while walking this place —endure in faith, and know Jesus Christ as the risen Saviour will enjoy God’s eternal rest. “Jesus said to the Jews who had believed Him, ‘If you abide in My word, you are truly My disciples’” (John 8:31). 

Endurance doesn’t save us, but it demonstrates our union with Christ. All those united to Jesus Christ must persevere and will persevere, not because of the power of their hope but because of the preserving power and grace of He who is the object of our faith.