Philippians 3:13-14
Brothers, I consider that I, myself, have not yet taken hold [of Christ's ultimate purpose for me]. But there is one thing that I am doing; I am forgetting about my past [See verses 5-7], and reaching forward to what lies ahead.
Hebrews 10:38
And my [i.e., God's] righteous person will [obtain] life by [his] faith [in God]. But if he turns back [from me], my soul is not pleased with him."
2 Peter 2:20-21
For if people who have escaped from the defiling practices of the world by coming to know our Lord and Savior Jesus Christ, become tangled up in them again, and are overcome by them, these people are worse off than before they were converted.