Perseverance, he teaches us, is due to the purpose of God, to the work of Christ, to the indwelling of the Holy Spirit, and to the primal source of all, the infinite, mysterious, and immutable love of God. - Charles Hodge

"It will be seen that the Apostle does not rest the perseverance of the saints on the indestructible nature of faith, or on the imperishable nature of the principle of grace in the heart, or on the constancy of the believer's will, but solely on what is out of ourselves. Perseverance, he teaches us, is due to the purpose of God, to the work of Christ, to the indwelling of the Holy Spirit, and to the primal source of all, the infinite, mysterious, and immutable love of God. We do not keep ourselves; we are kept by the power of God, through faith unto salvation. (1 Peter 1v 5.)

- Charles Hodge

Systematic Theology, Complete; Vol. 1: Introduction, Vol. 2: Part 1, Theology Proper; Part 2, Anthropology; Part 3, Soteriology; Vol. 3: Part 4, Eschatology