Baptism celebrates and seals the redeeming grace of God offered to all people. We believe the efficacy of Baptism is dependant on the love of God revealed in the death and resurrection of Jesus -- not on the faithfulness or insights of humans. It is celebrated as a joyful response to God - not an act of divine protection assuring salvation. As such, it is received only once; and Presbyterians affirm and accept all baptisms administered by other Christain denominations which use the element of water poured out in the name of the triune God.
In addition to celebrating God's covenant love, Baptism affirms our oneness with Christ and unity with fellow disciples in the Church. For adults who have not previously been baptized, the sacrament is celebrated when they join our congregation by professing their faith in Christ.
We are one of a few denominations who practice infant baptism. It manifests, in a powerful way, how reliant all of us are on God's love and grace. As is true for adults, infant baptism welcomes children into the life of our congregation - with members joining the parent(s) in pledging their support and encouragement for the ongoing spiritual development of a child. In that light, one can understand the Presbyterian requirement that at least one parent shall be an active member of the congregation administering the Baptism.
As revealed above, Baptism is about community -- the oneness we share with God through Christ and our bond with those in the Church. Therefore, Baptism is always celebrated as part of corporate worship -- it is never done privately.