We have a doctrine called the perseverance of the saints. I do not like that name for it; while saints do persevere, it is not because they have the power of perseverance within themselves. If it were left to me to persevere in my Christian walk, I would fall and stumble in a moment. The One who really perseveres is God. He perseveres with His children and thereby preserves them. One of the chief ways in which God preserves His people is through the priestly intercession of Jesus.