Sanctification is absolutely a part of your salvation, and an extremely crucial part at that. If you are faithful for 20 years and then decide to leave the race, you have neither endured until the end nor have you continued to abide in Jesus. Ergo, you have forfeited your salvation. There are NO Participation Trophies. Justification does NOT equal salvation! That is the past tense of salvation. You need the present tense and future tense of salvation in order to be saved. If you truly repented of your sins, trusted Jesus’ work on Calvary, and obeyed His teachings in the past, you MUST be repenting, trusting in Jesus, and obeying His teachings in the present, and will CONTINUE to repent, trust in Jesus, and obey His teachings in the future. You do NOT get to skip steps. There is NO 'Pass Go.’ STOP believing the LIES your preachers are feeding you and START believing Jesus and His Scriptures! Otherwise I suggest you start fearing for your soul. “NARROW is the way and FEW there are who find it.” I suggest ditching your religiosity and churchianity and embracing the biblical Christianity as taught in the New Testament Scriptures.
"He chose us in Christ...to be holy and blameless in His sight!" Ephesians 1:4
"God did not call us to be impure, but to live a holy life." 1 Thessalonians 4:7
"God has saved us, and called us to a holy life!" 2 Timothy 1:9
"Just as He who called you is holy, so be holy in all you do; for it is written: be holy, because I am holy." 1 Peter 1:15-16
"Pursue...holiness, without which no one will see the Lord" Hebrews 12:14