Well, it is not upon you, and it is surely not a mortal sin. The decision belongs to the priest, not to you. When a priest has certainty that the baptism was administered validly, he cannot simply repeat the baptism. That would be a sacrilege, because there is an indelible character, and the Church has forbidden this since ancient times. But when a priest has a serious doubt, and it must be a serious doubt, not just scrupulosity or a habit of doubting everything, he must inquire and ask about the circumstances. When there is a serious doubt, he can administer the sacrament of baptism conditionally. Administering it under the condition in such a case would be correct.
Dear visitors of Gloria Dei and all who have already written or who will write a personal message to me. I am grateful for your attention, your kindness, for your spiritual support and especially for your sacrifices and prayers for me. God may reward you!
