"Where is the scripture about the 12 apostles being baptized?" Regarding John the Baptist it was said: "And many of the children of Israel shall he turn to the Lord their God. And he shall go before him in the spirit and power of Elijah, to turn the hearts of the fathers to the children, and the disobedient to the wisdom of the just; to make ready a people for the Lord" (Luke 1:17,17). John was to make ready a people prepared for the Lord. How did he do this? Answer: "And he came into all the country about Jordan, preaching the baptism of repentance for the remission of sins" (Lk. 3:3). Every man that heard and believed the preaching of John, repented, and was baptized by him, received remission of sins, and in this way was made ready, prepared for the Lord. In contrast, those who refused to be baptized of John, rejected the counsel of God against themselves (Lk. 7:30). When Christ came and selected his apostles, they were from among his disciples, and His first disciples were assuredly of those baptized by John, and where thus made ready for Him. Therefore, the apostles were baptized by John in Jordan. To suppose that the Savior would select His apostles from among men that rejected the baptism of John, when John's mission was to make ready a people prepared for the Lord, is preposterous, especially so when those that rejected John's baptism rejected the counsel of God. Would Jesus have selected His apostles from those that rejected his Father? Moreover, God required Christ, His own Son, to be baptized of John before He had showed Himself to Israel and before He owned Him as His Son in the presence of the people; and Christ recognized the authority and will of the Father in the matter of baptism when He said to John, "Suffer it to be so now: for thus it becometh us to fulfill all righteousness" (Source consulted: Questions Answered, Lipscomb and Sewell,21-22). Regarding Paul, see Acts 22:16; 9:18; Rom. 6:3,4. Question may refer to whether they were re-baptized on the day of Pentecost, Acts 2. There is no record of that. The question of whether apostles or others baptized by John (before Acts 2) were baptized again after Acts 2 is a moot question. You do not know anyone who lived before Acts 2. All of us live after Acts 2. All of us are under the authority of the baptism of Christ, the baptism of the Great Commission.