The "baptismal life" names the Christian understanding that baptism is not a single completed event but the beginning of a whole manner of living, to be enacted and returned to every day. Especially in the Lutheran and wider Reformation traditions, though rooted in the theology of the early church and the Apostle Paul, baptism is understood as a dying and rising with Christ, the old self drowned and put to death, a new self raised to live before God, and the Christian is called to live out that death and resurrection daily, in continual repentance and renewal. Luther taught that the old Adam in the believer should be drowned by daily contrition and repentance and a new person daily arise, so that the one-time washing becomes the pattern of a lifetime.
On this view the whole of the Christian life is a living into what baptism signifies: the daily return from sin, the reliance on the grace received, and the growth into the identity conferred at the font. Believers are encouraged to "remember their baptism", not to repeat it, for the tradition holds it unrepeatable, but to recall and reclaim it as the ground of their standing before God and the source of their calling. The idea gives the sacrament an ongoing rather than merely initiatory force, framing repentance, faith and the moral struggle as the continual outworking of a single foundational grace, and it shapes the way these traditions speak of assurance, of the daily fight against sin, and of the believer's identity as a baptised child of God.