God is determined to save those who have trusted in Christ, and He who has begun a beneficial work in us will complete it until the day Christ returns and we see Him.
Christians worry about losing their salvation or worry about their ability to be faithful to God. Their focus is on the wrong person. Their focus should NOT be on their perseverance, but on the perseverance of God as Paul wrote in Philippians:
3 I thank my God in all my remembrance of you,
4 always offering prayer with joy in my every prayer for you all,
5 in view of your participation in the Gospel from the first day until now.
6 being personally confident of this very thing, that He who began a good work in you will bring it to completion until the day of Christ Jesus. (Phil 1:3-6)
God is determined to save those who have trusted in Christ, and he who has begun a beneficial work in us will complete it until the day of Christ Jesus. The day of Christ Jesus is the time when Jesus returns and we see him. It is the work of the Trinity to safely get us there. The Father has justified us, the Son is protecting us, and the Holy Spirit is the down payment of our salvation.