To smack or "bap" someone upside the head or forehead. Can be used in reference to shows (etc.) that consist of someone believed to be a healer doing the work of God. These said "healers" will violently thrust their hand upon (bap) the person needing healed's head, forehead, or face. This is intended to cure said victim.
From Greek baptizien:
To affect thoroughly for purification, to renew or establish a relationship with God.
Implication:
Jesus was baptised on the cross at Calgary because He was thouroughly affected by 'the payment of the ransom held by Satan for humanities sin' and His love was purified (void of hate), and humanity could now renew or establish a relationship with Him; God; our Father; our Creator.
"And I myself did not know him, but the one who sent me to baptize with water told me, ‘The man on whom you see the Spirit come down and remain is the one who will baptize with the Holy Spirit.’"
John 1:33 NIV