The following is a quote from a talk from the October 2017 General Conference that shows that the priesthood LDS hold is not “another” priesthood authority independent of Christ’s, but simply our participation in the priesthood of Christ, as well as the central role priesthood plays in LDS soteriology (such topics, and others, are discussed in my book, "After the Order of the Son of God": The Biblical and Historical Evidence for Latter-day Saint Theology of the Priesthood):
Because of His atoning sacrifice, Jesus Christ has the power and authority to redeem all mankind. To make His atoning power accessible, He has delegated a portion of His power and authority to men on earth. This delegated power and authority is called priesthood. It permits priesthood holders to help Heavenly Father and Jesus Christ in Their work—to bring about the salvation and exaltation of God’s children. It does so because it provides His children the opportunity to receive the blessings of the Savior’s atoning power . . .For Heavenly Father’s purposes to be accomplished. Christ’s atoning power needs to be made available to God’s children. The priesthood delivers these opportunities. (Elder Dale G. Renlund, The Priesthood and the Savior’s Atoning Power)