Summary: The symbol of Aaron's mitre and bonnet hold great truths for the NT believer.
Exodus 28:1-3 KJV And take thou unto thee Aaron thy brother, and his sons with him, from among the children of Israel, that he may minister unto me in the priest's office, even Aaron, Nadab and Abihu, Eleazar and Ithamar, Aaron's sons.  And thou shalt make holy garments for Aaron thy brother for glory and for beauty.  And thou shalt speak unto all that are wise hearted, whom I have filled with the spirit of wisdom, that they may make Aaron's garments to consecrate him, that he may minister unto me in the priest's office.
Exodus 28:39-40 KJV And thou shalt embroider the coat of fine linen, and thou shalt make the mitre of fine linen, and thou shalt make the girdle of needlework.  And for Aaron's sons thou shalt make coats, and thou shalt make for them girdles, and bonnets shalt thou make for them, for glory and for beauty.
Exodus 39:28 KJV And a mitre of fine linen, and goodly bonnets of fine linen, and linen breeches of fine twined linen,
Leviticus 16:4 KJV He shall put on the holy linen coat, and he shall have the linen breeches upon his flesh, and shall be girded with a linen girdle, and with the linen mitre shall he be attired: these are holy garments; therefore shall he wash his flesh in water, and so put them on.
I. INTRODUCTION—THE FORCE OF SCRIPTURE
One of the most compelling things about Scripture is its authority. Furthermore, if we believe the authority of Scripture then we will come to a belief in the sufficiency of Scripture. By sufficiency of Scripture, it is meant that one can have confidence in knowing that every problem of life has a solution found in the Word of God. The very nature of the authority of Scripture gives to us the understanding that there are multiple places in the Word of God that gives to us the same answer.
The more familiar that we become with Scripture, the more one can see a consistency that is noted throughout its pages. The whole goal of the preached Word is the sanctification of the church of God. A true apostolic church can never minimize the work of the Word! As the Word is unfolded to us, there are characteristics of holiness and godliness that began to take place in our lives. It gives a sense of mission and motivates sacrifice.
Paul noted the goal for his dedication to the preaching and teaching of the Word:
Galatians 4:19 KJV My little children, of whom I travail in birth again until Christ be formed in you,
Ephesians 4:11-15 KJV And he gave some, apostles; and some, prophets; and some, evangelists; and some, pastors and teachers;  For the perfecting of the saints, for the work of the ministry, for the edifying of the body of Christ:  Till we all come in the unity of the faith, and of the knowledge of the Son of God, unto a perfect man, unto the measure of the stature of the fulness of Christ:  That we henceforth be no more children, tossed to and fro, and carried about with every wind of doctrine, by the sleight of men, and cunning craftiness, whereby they lie in wait to deceive;  But speaking the truth in love, may grow up into him in all things, which is the head, even Christ: