The following extract is taken from a marvellous post at VULTUS CHRISTI BLOG:A Priest's One Necessary Sermon:http://vultus.stblogs.org. Please take the time to go there and read the whole post by Dom Mark Daniel Kirby.
A Priest's One Necessary Sermon
The Lamb who is adored in the glory of heaven is present in the Most Holy Sacrament of the Altar here on earth. If a priest were to preach but one sermon from the day of his Ordination until his death, that one sermon could be this:
Ecce Agnus Dei, ecce qui tollit peccata mundi;
Behold the Lamb of God, behold Him who taketh away the sins of the world (John 1:29).
Disappear Into Adoration
The priest is but a herald. He announces the presence of the Immolated Lamb, and then annihilates himself in humble adoration. Adoration leads inexorably to self-effacement. The Lamb is exalted; the herald of the Lamb disappears. The Bridegroom shines forth in all His beauty; the friend of the Bridegroom withdraws, content to listen to the sound of his voice.
A priest's adoration -- be it expressed in the liturgical rites (and especially at Holy Mass) or in silence before the Blessed Sacrament -- a priest's adoration is his praedicatio prima, his primary preaching. Without the praedicatio prima of adoration, no other preaching has credibility or meaning.
Preparing for Heaven
The priest who adores does on earth, does what the angels and saints do in heaven. He is employed on earth in the worship of the Lamb that will be his everlasting employment, his rest, and his glory in heaven.
The Compass That Orients One's Priesthood
The priest who is not first an adorer has lost the compass that orients all the rest of his life. The priesthood is ordered to adoration, and the summit of adoration is sacrifice: the immolation of a victim to God. The loss of the spirit of adoration is the ruin of the priesthood.
The truth is here expressed with marvellous clarity.