John Nelson Darby explores the distinctions between the Aaronic and Melchisedec priesthoods, emphasizing that the Aaronic priesthood serves as a provisional means for addressing evil without judgment, while the Melchisedec priesthood represents a higher calling of royalty and blessing for all nations. He highlights that Christ, as a priest after the order of Melchisedec, not only intercedes for sinners but also blesses both the people and God, establishing a perfect union with Him. Darby stresses the importance of understanding our identity as kings with Melchisedec and the dual roles of mediation and union in our relationship with Christ, who maintains our communion with God through His righteousness. The sermon concludes with the notion that while we were once slaves in Egypt, we are now conquerors in the promised land, symbolizing our victory through Christ.

(extracted from Simple Testimony, 1845) The Aaronical priesthood is provisional for evil without reference to judgment. In it we have purity, discerning between good and evil, entering into the holiest, intercession, and blessing by virtue of sacrifice before Aaron came down. Lev. 9:22. This Christ is now, as to service, while He is priest after the order of Melchisedec. We understand our title to royalty in Melchisedec, priest of the most high God, possessor of heaven and earth; not merely the God of Israel but the God of the whole earth, — the gods of the Gentiles all set aside, and the Lord Jesus the centre and minister of all this blessing; blessing the people, and blessing God for the people, not merely interceding for sinners; though this is the foundation of the other. But after all, we are not to consider the Melchisedec, in one sense, higher than the Aaronic. We are kings with Melchisedec. The King becomes priest: this is perfection. It is not, in one sense, perfection to have the Lord Jesus Christ interceding for our imperfection: but out blessing is, to be associated with Him in all His blessing. He becomes Mediator to the earth of blessing, specially to the Jews, but to the whole earth. As regards Aaronic priesthood, we get another thing — present mediation for the church. We must always hold these two things — mediation and union. Christ's intercession for us is to maintain our communion wit God in the righteousness we are made in Him. Our union with Him is in resurrection; and we are brought into conflict wit the Canaanites because redeemed out of Egypt. We were slaves of Pharaoh, but are conquerors of the Canaanites.