D&C 20

President Boyd K. Packer said "An ordination to an office in the priesthood is permanent and follows the one ordained wherever he goes. Except for transgression, he is never released." (Worldwide Leadership Training Meeting, June 21, 2003)

53 The teacher's duty is to watch over the church always, and be with and strengthen them;
54 And see that there is no iniquity in the church, neither hardness with each other, neither lying, backbiting, nor evil speaking;
55 And see that the church meet together often, and also see that all the members do their duty.
56 And he is to take the lead of meetings in the absence of the elder or priest—
57 And is to be assisted always, in all his duties in the church, by the deacons, if occasion requires. (Doctrine and Covenants Section 20:53 - 57)

This being the case, the teacher's duty becomes the duty of all priesthood holders(including the deacon, if occasion requires). This becomes a duty we cannot be released from. Isn't this what home teaching is all about? To "teach, expound, exhort...and visit the house of each member, and exhort them to pray vocally and in secret and attend to all family duties."
(Doctrine and Covenants Section 20:46 - 47)

Just another thought - baptism and membership in the Church is not to be an arbitrary thing -

"...concerning the manner of baptism—All those who humble themselves before God, and desire to be baptized, and come forth with broken hearts and contrite spirits, and witness before the church that they have truly repented of all their sins, and are willing to take upon them the name of Jesus Christ, having a determination to serve him to the end, and truly manifest by their works that they have received of the Spirit of Christ unto the remission of their sins, shall be received by baptism into his church.
(Doctrine and Covenants Section 20:37)

And of Baptism and partaking of the sacrament -

69 ...the members shall manifest before the church, and also before the elders, by a godly walk and conversation, that they are worthy of it, that there may be works and faith agreeable to the holy scriptures—walking in holiness before the Lord.
(Doctrine and Covenants Section 20:69)

This is why we have baptismal interviews, temple recommend interviews, priesthood interviews, youth interviews, and so forth to "manifest before the church".