The doctrine of the keys of the priesthood is perhaps one of the most important, but least understood of all the doctrines of the Church. It is also one of the most difficult to explain to people who are not members of the Church, but it is a very important doctrine and has had and will have a great impact on not only the Church but everyone else as well.
Before writing this post I looked up a few reference articles about the keys of the priesthood and found a few excellent resources about priesthood keys. Here is a link to the chapter on priesthood keys in the Melchizedek Priesthood manual. There is also a good talk about priesthood keys by Elder Nelson that appeared in the October Ensign in 2005. For those who want to learn more about the priesthood keys that is a good place to start. The rest of this post assumes that the reader has some understanding of the priesthood and priesthood keys.
Usually in the Church when we talk about priesthood keys we are referring to the active aspects of priesthood keys, that is, what they are used for in creating the structure and organization of the Church. While this aspect of priesthood keys is very important, there is another aspect that is very commonly over looked and very poorly understood. This aspect is more passive in its effect, but is still just as necessary and central to the doctrine of priesthood keys. It also brings together many other seemingly disparate doctrines of the Church and acts as central tie that binds the doctrine together.
First I will explain the more commonly known active aspects of the keys and then I will use that to explain the less well understood passive aspects of the keys. The active aspects are those things that have to do with priesthood authority and the power to organize the various stakes of Zion, organize the work of preaching the gospel and the functioning of temples. In all these cases priesthood keys are needed in order to preside and to allow for proper functioning of the organization. In each organization (i.e. stake, mission, temple) there is a president who has the keys, or the power, to order the formation of the organization. Typically when we talk about the keys in the Church, this is what we refer to. These aspects of priesthood keys involve the calling and setting apart for callings, the blessing of the sick, the performance of ordinances and the authority to interpret doctrine and give counsel and guidance. Without priesthood keys, none of these things could legitimately be done, with authority, and with efficacy. The keys are separate from the ordination to the priesthood, in that only certain men who hold the priesthood can hold and exercise keys, and they can only exercise the keys in a presidency, in order to preside, whereas all men can hold the priesthood.
The key here (no pun intended) is that in order for the priesthood keys to become operative there must be some action taken by those who hold the keys. Without the active participation of the person who holds the keys then the keys are dormant and of no effect. In order to use the keys the holder must exercise them within a presidency, which means they must have the proper authority and calling to exercise the keys first.
The second aspect of priesthood keys is what I will refer to as passive, although there must still be action taken on the part of someone in order to make the keys operative, but the actual holder of the priesthood keys need not do anything, or even be entirely worthy to allow this aspect of priesthood keys to work. The purpose of these particular priesthood keys is not dealing with the organization of the church but rather with the spiritual blessings of the priesthood as outlined in D&C 107:18-20.
18 The power and authority of the higher, or Melchizedek Priesthood, is to hold the keys of all the spiritual blessings of the church—In verse 19 there are several "spiritual blessings" mentioned, including receiving the mysteries of the kingdom of heaven and to enjoy the communion and presence of God the Father, and Jesus, but in order to enjoy these spiritual blessings someone must first "hold the keys". These blessings listed in verse 19 are what I am referring to as the passive keys of the priesthood. Not all priesthood holders will hold these keys, but for those that do they play a very important role for the rest of us. Simply by holding the keys, even if the holder do not do anything, or even if they are not entirely worthy, then the keys become operative and anyone who is faithful will have access to the spiritual blessings given in verse 19. Without someone to hold the keys, it does not matter how faithful someone is, or how righteous they are, or who they are or what they have done, if no one on the earth holds those priesthood keys, then they cannot have access to those blessings.
Furthermore, the blessings, because they are part of the Melchizedek Priesthood, are only available through a quorum. This means that in order for a priesthood holder to take advantage of these spiritual blessings then they must be a member of a priesthood quorum where the president holds the keys mentioned above. Without a quorum (and by definition a president who holds the keys of presidency in the quorum) a priesthood holder is without access to these blessings, because the keys are given to the president of the quorum, and the members of the quorum thereby have access through the passive use of the keys. It is interesting to note that this realization means that in order for a priesthood holder to have access to these blessings they must not only be a member of a quorum, but they must also be an active member of that quorum. This is to say that the more they are active and participate in their quorum, the more they have access to these blessings. But the only way they will have access is if the president of their quorum holds the keys to the blessings. The president does not need to do anything for the members of his quorum to access these blessings other than to have the keys conferred upon him.
Previously I stated that the person who holds the keys need not be entirely worthy to allow the passive keys to be operative. What I meant by that is that the ability of the individual members of the quorum to access the blessings is not entirely determined by the righteousness of the president but rather the individual members. This means that someone's ability to receive blessings is not determined by the level of spirituality of the holder of the keys. But having said this, by the very nature of priesthood keys these blessings cannot be accessed by an individual, no matter how righteous or faithful he is. These keys are only operative when the individual is an active member of his quorum. And the quorum is only active and conducive to the dispensing of the these blessings when the members, particularly the president are involved with each other, and living righteous lives. Thus while a faithful individual will not be denied the blessings as long as someone holds the keys, they will only be able to reap blessings in proportion to the activity of their quorum.
A good analogy would be the level of peace in a community. An individual may be at peace with himself and others, but unless those around him are also at peace then the individual, no matter how good, or how peace-like he is, will not have peace in his community and will not be able to enjoy the blessings or advantages of living in a peaceful community. But the more peace-like those around him are, the more peace the individual will be able to enjoy.
So in conclusion, the keys of the priesthood are manifest through the active aspect, namely the calling and setting apart of individuals for the organization and guidance of the Church, and the passive aspect, which requires no action on the part of the holder of the keys, but the level of blessings (as given in D&C 107:19) that are available are directly proportional to the righteousness of the individual members of the quorum and more particularly the president of the quorum. They key lesson here is that while these blessings are given to individuals, and thus depend of the righteousness of the individual in order to receive the blessing, it is not possible to access the blessings as an individual, but only through the community of saints. Individuals receive the blessings, but individuals cannot provide access to the blessings. No man can gain salvation or receive blessings or knowledge from God alone.
As a final note, there are other keys of the priesthood not mentioned in D&C 107 but are mentioned in D&C 110 that are not operative only in priesthood quorums, but are operative through out the world, both inside and outside the Church (some of them more particularly outside the Church). Again these things would not be possible if it were not for the fact that someone holds the keys to these special things. The holder of the keys need not do anything in particular to make these things operative other than hold the keys. These things include the gathering of Israel and the spirit of Elijah, both of which are fairly extensive topics, which I will not cover here. These keys are different from the other keys mentioned, because these keys are not typically delegated to the local quorum presidents, but reside with the presiding high priest of the Melchizedek Priesthood, who is the president of the Church. While these keys are not "local" they are operative because someone holds them. The blessings, the work and the effects of these priesthood keys would not be seen if it were not for the presence of the keys on the earth.