Today is the 183rd Anniversary of the Restoration of the Aaronic Priesthood.
On May 15th, 1829, John the Baptist (as a resurrected being, see Matthew 27:52-53 and 3 Nephi 23:11) came to Joseph Smith and Oliver Cowdery on the bank of the Susquehanna River. He then Ordained them to the Priesthood which he held, which is the same Priesthood that Christ was Baptized by.
Without this Authority nothing that we do in this life would be of any effect out of this life.
When asked who the Apostles said Jesus was, Peter replied,
It was upon this, the Testimony of the Godhead, that is the keystone of the Church, upon which the Devil has no power to overthrow.
Christ then stated:
It is through this Sealing Power, to bind on Earth and in Heaven, that we may be with our Families Forever.
Without the proper Authority of the Priesthood, nothing done in any religious ceremony is of any effect after we depart this life. Only by doing what God has Commanded, in the way He commanded it, may we truly be saved at the last day.