Baptism is the ordinance by which Christ's people are publicly identified with Him. It is the visible sign of the new covenant, parallel to circumcision in the old. Jesus commanded it in the Great Commission: "Go therefore and make disciples of all the nations, baptizing them in the name of the Father and of the Son and of the Holy Spirit" (Matthew 28:19). Paul describes its theological meaning: "Or do you not know that as many of us as were baptized into Christ Jesus were baptized into His death? Therefore we were buried with Him through baptism into death, that just as Christ was raised from the dead by the glory of the Father, even so we also should walk in newness of life" (Romans 6:3-4). Baptism pictures the gospel: going under the water is identification with Christ's death and burial; coming up out of the water is identification with His resurrection. Christians have long disagreed about two aspects: (1) Mode — immersion (full submersion, the standard Baptist practice), pouring (affusion), or sprinkling (aspersion). The Greek word baptizo means "to immerse," and the New Testament examples (Jesus "coming up immediately from the water" in Matthew 3:16, the Ethiopian eunuch going "down into the water" in Acts 8:38) favor immersion, though the early church practiced other modes when water was scarce. (2) Subjects — believers only (Baptist, credobaptist position) or also infants of Christian parents (paedobaptist position held by Presbyterian, Reformed, Lutheran, Catholic, Anglican, Orthodox). Both sides appeal to covenant theology and baptism's relation to circumcision. All orthodox Christians affirm: baptism does not save (that is baptismal regeneration, rejected by most Protestants), but it is commanded, not optional. Every disciple of Christ is to be baptized. It is the first step of obedience, the public confession of new life, and a means of grace as the Spirit uses it to strengthen faith.