Reformed theology maintains that baptism is a sign of God's covenant grace that is to be administered only once, as it represents the singular work of Christ in our union with Him. While Presbyterian traditions practice infant baptism as a sign of entry into the covenant community, many Baptists practice credobaptism upon profession of faith; however, both perspectives generally agree that re-baptism is unnecessary for those who have already received the sign in the name of the Triune God.
Reformed theology emphasizes that baptism, being a sign and seal of our ingrafting into Christ, is to be administered only once. explicitly states that the sacrament is but once to be administered, reflecting the biblical truth that we are born into the kingdom of God only once. As the teaches, since we cannot be born twice, our baptism is a singular, perpetual testimony of God’s grace that continues throughout the whole course of our life. This is not because the water itself has saving power, but because the ordinance is a sign of the blood of Christ and the work of the Holy Spirit. To seek baptism again suggests that the initial administration was ineffective, which undermines the sufficiency of Christ’s covenant promise. Reformed theologians hold that even if one was baptized in infancy, that sign remains valid as a testament to God's gracious inclusion of the believer and their offspring into the community of the faithful.
The Reformed practice of infant baptism rests on the conviction that the children of believers are included in the covenant of grace. According to , infants are to be admitted into the church as a sign of the covenant, just as children in the old covenant were circumcised as a sign of the righteousness they received by faith, as seen in . The reinforces this by stating that infants descending from parents who profess faith in Christ are within the covenant and therefore to be baptized. This stands in contrast to the Credobaptist view, which requires a conscious profession of faith before baptism. However, within the Reformed family, the consensus remains that once this sign of initiation has been applied—whether in infancy or adulthood—the ordinance is complete. The efficacy of the sacrament depends not on the age of the recipient or the specific time of administration, but on the faithfulness of God who promised to be the God of the believer and their descendants.
The Reformed tradition demonstrates significant variety in its approach to baptismal practice. Presbyterians, following the Westminster Standards, emphasize covenant continuity and the baptism of children of believers (). Continental Reformed traditions, as reflected in the , also affirm this paedobaptist position. In contrast, the 1689 London Baptist Confession of Faith (1689 LBCF) represents the Particular Baptist tradition, which maintains that baptism is only for those who have made a credible profession of faith (). While the Anglican position, stated in the , strongly defends the retention of infant baptism as agreeable with Christ's institution, other Baptist traditions view infant baptism as lacking the required response of faith. Despite these differences regarding who should be baptized, there is a strong historic consensus across these traditions that re-baptism is not to be performed. Each tradition maintains that the seal of the covenant, once applied through water and the Word, is a finished work of initiation into the life of the church.
The comfort of the gospel is that our status before God does not rely on our perfect understanding of a ritual at the time it was performed, but on the finished work of Jesus Christ. As Paul writes in , believers have been circumcised with a circumcision performed by Christ and buried with Him in baptism. This signifies that we have been made alive in Christ through faith in God’s power. Whether you were baptized as an infant in the church or as an adult upon profession of faith, the grace signified is the same: the cleansing of your sins by the blood of Christ. If you feel that your baptism as an infant did not reflect your own personal faith, you may find assurance in the fact that baptism is a work of God initiated towards you, not a work of yours initiated toward God. You are held by Him, and your identity is rooted in His promise, not in the chronological timing of the water applied to your head. Rest in the reality that Christ has already claimed you, and focus your heart on the life of repentance and faith that your baptism signifies.