The C&MA affirms that all humans are born with a sinful nature inherited from Adam. Through Adam's transgression, sin entered the world and death through sin, and all people are born into this fallen condition. This doctrine is affirmed in the C&MA Statement of Faith and foundational to its understanding of salvation. The sinful nature is not merely external acts of disobedience but an inward corruption of the will, heart, and inclination toward evil.

However, the C&MA distinctive teaching on sanctification shapes its understanding of original sin. The C&MA teaches that while justification removes guilt and penalty, it does not immediately eradicate the sinful nature (the "carnal nature" in C&MA terminology). Through the work of the Holy Spirit in sanctification, particularly through the experience of Spirit baptism and yielding to Christ as Sanctifier, believers can progress toward victory over the indwelling sinful nature and grow in holiness. This is not sinless perfection but progressive sanctification — a deepening work of grace over the lifetime of faith.

The presence of prevenient grace, however, means that even fallen humans are not totally depraved in the sense of being unable to respond to God's call. God's grace precedes conversion and enables the sinner to believe. Thus, while original sin is real and universal, it does not render humans incapable of responding to the gospel.