Perseverance of the Saints
I have been asked is it not inconsistent to declare we believe salvation is all of grace and at the same time believe in the final perseverance of the saints. The question reveals a misunderstanding of the doctrine of perseverance. Salvation is of the Lord. The Father planned it, the Son accomplished it and the Spirit applies it; but the evidence that a person has been born again is that he continues following the Lord.
Perseverance is not a work performed by the sinner as a contribution to his salvation but evidence that he has been saved.
A true believer may have many failures along the way, but he will not finally turn away. “They went out from us, but they were not of us; for if they had been of us, they would no doubt have continued with us: but they went out, that they might be manifest that they were not of us” (I John 2:19). The desire of the child of God is to live righteously but because the old nature has not been eradicated, he struggles and often stumbles, but when a person denies the faith it is evidence, he never was a true believer.
The fact is the true believer perseveres because he is persevered. “Being confident of this very thing, that he which hath begun a good work in you will perform it until the day of Jesus Christ” (Philippians).