Lutherans believe that the Bible teaches that a person is saved by God’s grace alone through faith in Jesus Christ alone. The Bible tells us that such “faith comes by hearing” (Rom 10:17). Jesus Himself commands Baptism and tells us that Baptism is water used together with the Word of God (Matt 28:19-20). Because of this, we believe that Baptism is one of the miraculous means of grace (another is God’s Word as it is written or spoken), through which God creates and/or strengthens the gift of faith in a person’s heart (see Acts 2:38; Acts 22:16; 1 Peter 3:21; Gal 3:26-27; Rom 6:1-4; Col 2:11-12; 1 Cor 12:13).
Although we do not claim to understand fully how this happens, we believe that when an infant is baptized God creates faith in the heart of that infant. We believe this because the Bible says that infants can believe (Matt 18:6) and that new birth (regeneration) happens in Baptism (John 3:5-7; Titus 3:5-6). The infant’s faith cannot yet, of course, be verbally expressed or articulated by the child, yet it is real and present all the same (see e.g., Acts 2:38-39; Luke 1:15; 2 Tim 3:15). The faith of the infant, like the faith of adults, also needs to be fed and nurtured by God’s Word (Matt 28:18-20), or it will die.
Lutherans do not believe that only those baptized as infants receive faith. Faith can also be created in a person’s heart by the power of the Holy Spirit working through God’s (written or spoken) Word. Baptism should then soon follow conversion (cf. Acts 8:37) for the purpose of confirming and strengthening faith in accordance with God’s command and promise. Depending on the situation, therefore, Lutherans baptize people of all ages from infancy to adulthood.
We also do not believe that Baptism is ABSOLUTELY necessary for salvation. The thief on the cross was saved, as were all true believers in the Old Testament era. Mark 16:16 implies that it is not the absence of Baptism that condemns a person but the absence of faith, and there are clearly other ways of coming to faith by the power of the Holy Spirit (reading or hearing the Word of God). Still, Baptism dare not be despised or willfully neglected, since it is explicitly commanded by God and has His precious promises attached to it. It is not a mere “ritual” or “symbol,” but a powerful means of grace by which God grants faith and the forgiveness of sins.