The answer
The Holy Sacrament of Baptism can only be administered once. In the history of the early church, during the papacy of Abba Dionysius (14th), when many people were persecuted and out of fear denied their faith but later repented, they were allowed full inclusion back in the church based on their sincerity and did not require re-baptism. This issue was placed amongst the agenda in the First Ecumenical Council of Nicea. Pope Peter the Seal of Martyrs (17th) also reinforced this official decree after trying to baptize a woman's two sons whom the mother had baptized in the sea fearing they would die before they reached the church for the children to be baptized there. Each time Pope Peter tried to immerse the children in the water, he could not because each time the water turned into stone. By learning the events from the mother regarding how they came to be baptized by her blood, he also declared and reinforced one baptism only.
Answered by His Eminence Metropolitan Youssef (opens in a new tab)