John the Baptist, being from the tribe of Levi, had the Levitical priesthood and the authority to baptize Christ. Christ was born holding the Melchizedek Priesthood and did not need to be confirmed a member of His own church nor the gift of the Holy Ghost confirmed upon him. My question is; when did Christ give his apostles the Melchizedek Priesthood? Was it on the day of Pentecost or when they were called to be Apostles?
When the Savior chose His twelve apostles He ordained them to the same office. Matthew records that when He called the twelve, “he gave them power against unclean spirits, to cast them out, and to heal all manner of sickness and all manner of disease” (Matt 10:1). They are even given a charge to exercise this power in their missionary labors (Matt 10:8). If there’s any doubt remaining, Mark and John specifically say they are ordained to this (Mark 3:14, John 15:16).
Both Mark and Luke toss in a few sermons in between the time Jesus calls the apostles and when He commissions them (Mark 6:7-13, Luke 6:12-16, 9:1-2). So it is possible that the apostles were not ordained at the same time as their call, but it would have been a short time afterward.
I feel the need to comment on your other statements. I don’t think anyone is born with the priesthood, let alone an office. Because of his lineage, John had a natural right to the priesthood (and to the office of Priest). It sounds like you think the Son of God was an exception, who needed the saving ordinance of baptism but not confirmation or ordination to the priesthood. If this is a true doctrine it is certainly a new one. Treasure it up in your heart until such a time that it is publicly revealed.