Why is salvation considered a mystery for Christians?

Salvation is described as a mystery because it transcends human comprehension and operates through divine revelation. As Paul explains in 1 Corinthians 2, the natural man cannot understand the things of God, as they are spiritually discerned (1 Corinthians 2:14). The transformation that occurs during salvation is a work of the Holy Spirit; it awakens a person from spiritual blindness to the glorious truth of Christ (Ephesians 2:1-5). This mystery not only encompasses the act of being saved but also the ongoing work of grace in the believer's life as they grow in faith and obedience.