1 Chronicles 6:49 "But Aaron and his sons made offerings upon the altar of burnt offering and upon the altar of incense for all the work of the most holy place, and to make atonement for Israel, according to all that Moses the servant of God had commanded."

This is right after David had brought the ark of the covenant to its new home in the tent of meeting, so obviously it is Aaron's descendants who are actually making the offerings. The offerings are to bless the work that has been done "in this holy place", and to make atonement for Israel.

Although Jesus has replaced the sacrificial offerings that Aaron and his sons made, the sacrificial offering for atonement still takes place at every Catholic Mass. The priest, in persona Christi, reoffers Jesus' sacrifice to the Father to make atonement for us, all of God's children.

What a beautiful and absolutely essential role priests have! Without our priests, we would not have the Eucharist, we could not have the relationship with God that He wants us to have! St. Padre Pio said “It would be easier for the world to survive without the sun than to do without Holy Mass.” And the Holy Mass could not continue without priests. That is how essential they are! Let's pray for all of them today, living and deceased, and pray for more of them, so the Mass and the world continue.