For as many of you as have been baptized into Christ have put on Christ. --Galatians 3:27
def v to dip or submerge, immerse
The event spoken of by the Apostle Paul here in Galatians and in Romans 6:3 and 1 Corinthians 12:13 is not the ceremonial immersion of being dipped in water that is so frequently given as the complete definition to the word "baptize". Instead, this event occurs when a believing sinner first puts his faith in Jesus Christ for the forgiveness of sin and the justification from God. When the sinner is born again, the Holy Spirit places that new believer in vital union with Christ. That soul is now united with Christ.
By placing the believer into Christ the believer can now break the sin nature that had him imprisoned. The divine life is now implanted and new life energized by the Holy Spirit's direction can now form.
The new life spoken of here and in Roman 6 is not automatic. Only as the believer submits to the Holy Spirit, says "no" to sin and "yes" to the leading of God can the fulness of life in Christ be realized. The ongoing sanctification -- the living faith -- begins with this first act the Holy Spirit does for each and every new believer.