Therefore, if perfection were through the Levitical priesthood (for under it the people received the law), what further need was there that another priest should rise according to the order of Melchizedek, and not be called according to the order of Aaron? (Hebrews 7:11)

Today’s big question: why did we need a new Priest?

Do you know what the leading cause of death is in the world today? The real answer is: life. This is because everyone is a sinner and the wages of sin is death.

Every person who is conceived dies. It’s a sad fact. How many times have we seen someone pin his hopes on another person, only to be disillusioned when that person finally meets their end? Pinning our hopes on people is never going to bring true fulfillment and satisfaction. This is why the priests of Israel could never be the answer for our sin problem. They could only point to the answer. They could only be a picture, shadow, or copy of the real answer—Jesus.

Every human priest had a beginning and sadly, an end. “Also there were many priests, because they were prevented by death from continuing” (Hebrews 7:23). The priest would complete the sacrifice on behalf of the people and of themselves. Then they would die and another priest would take over this duty. It would happen over and over again. No satisfaction was found in the priest, except for the fact that every action they were required to peform pointed to that which would result in ultimate satisfaction. Who could fulfill this priesthood? Who could be the undying priest?

Jesus was not a normal Priest. He was a Priest in the order of Melchizedek. We read in Genesis 14 that Melchizedek was a king. Hebrews also tells us that Melchizedek had no recorded beginning and no recorded ending. This is a great picture of Jesus, who fulfilled the priesthood.

He is not only Priest but He is also King. He is the one without beginning and end because He is God. When Jesus went into the holy of holies as our once-and-for-all sacrifice, He had completed all the requirements of the priesthood. He who was without beginning and without sin, took on our sin, suffered the wrath of an eternally righteous God, rose from the grave in full victory, and is now exalted forevermore.

Jesus is an entirely different Priest. There is no need for another to come after Him because He will never die. All our hope is in our great Substitute. The actions of many priests for the Jews has been superseded by one great High Priest for all people, and now we all share with our kingly Priest in being His royal priesthood.  http://www.answersingenesis.org/articles/2011/03/14/need-a-new-priest