This is EXTREMELY Rough, so I will be revising it, but here is a first go. The point is that the ministrations described D&C 76 are a sort of “grand order” of priesthood (and family) ministration in mortality as well as after the resurrection. The celestial can receive the fullness of the Father. The celestial minister to the terrestrial, who can enjoy the presence of the Son. The terrestrial minister to the telestial, who cannot go where the father and the son are, so that the telestial can receive the presence of the member of the remaining member of the Godhead, the Holy Ghost.
The point is also that we as progressively receive more, and more of the laws of God’s kingdoms, we also receive the corresponding spiritual blessings, precisely as they are laid out in D&C 76 (and elsewhere).
At baptism we do not receive the full celestial law. I realize that might sound surprising. After all, baptism is the gate onto the path of the celestial kingdom.
There is one route to answering this that I take in my book on the atonement. Here I will take a different route. It is that if we understand the terms by which we may gain a spiritual blessing here then we understand the terms by which we may gain that spiritual blessing before this life or after this life. Spiritual principles remain the same and any spiritual principle you understand here will be the same in the spirit world as well as in the post mortal spirit world.
D&C 130:18 Whatever principle of intelligence we attain unto in this life, it will rise with us in the resurrection.
19 And if a person gains more knowledge and intelligence in this life through his diligence and obedience than another, he will have so much the advantage in the world to come.
Now there is more to this.
The scriptures speak of a telestial law, and terrestrial law, and a celestial law.
And this can be a very confusing thing for people, because when they hear the term telestial law, they naturally assume that a telestial law is whatever remnants of goodness is found in those people that are living so badly that they will go to the telestial kingdom.
But that is not what the scriptures teach at all.
D&C 88:24 And he who cannot abide the law of a telestial kingdom cannot abide a telestial glory; therefore he is not meet for a kingdom of glory. Therefore he must abide a kingdom which is not a kingdom of glory.
The telestial law is the law those people will be willing to live AFTER having repented of their sins, enduring the pains of a damned soul in hell during the millenium. The scriptures state that the telestial will all bow the knee before Christ, and will be his servants. They will no longer be rebellious. This will all be done BEFORE they enter the telestial kingdom. Thus the telestial law has nothing to do with the wicked behavior found in a fallen world. It is the law of a glorified telestial kingdom and to live it one has to repent, confess Christ, and become a servant of the Most High.
D&C 76: 109 But behold, and lo, we saw the glory and the inhabitants of the telestial world, that they were as innumerable as the stars in the firmament of heaven, or as the sand upon the seashore;
110 And heard the voice of the Lord saying: These all shall bow the knee, and every tongue shall confess to him who sits upon the throne forever and ever;
111 For they shall be judged according to their works, and every man shall receive according to his own works, his own dominion, in the mansions which are prepared;
112 And they shall be servants of the Most High; but where God and Christ dwell they cannot come, worlds without end.
Those living a telestial law enjoy spiritual blessings for doing so.
D&C 76: 86 These are they who receive not of his fulness in the eternal world, but of the Holy Spirit through the ministration of the terrestrial;
88 And also the telestial receive it of the administering of angels who are appointed to minister for them, or who are appointed to be ministering spirits for them; for they shall be heirs of salvation.
Those living a telestial law can receive of the Holy Spirit through the ministration of the terrestrial, as well as through the administering of angels.
And now we come to the meat of the matter. The scriptures say the telestial can receive the Holy Ghost. On what terms? Why, on the same terms that we can receive the Holy Ghost. They must repent. They must accept Christ as their King and Savior. They must become his servant. These requirements of the telestial law allow them to enjoy spiritual cleanliness and spiritual gifts the same as such requirements allow us to enjoy spiritual cleanliness and spiritual gifts.
D&C 88:34 And again, verily I say unto you, that which is governed by law is also preserved by law and perfected and sanctified by the same.
The strait and narrow path can be viewed as no different than a ladder that climbs through the kingdoms of glory from the very lowest to the fullness of the highest. We start at baptism on the lowest rung, the beginnings of the telestial law. Then we climb by learning to obey that portion we have received. In time, we are given more through the endowment, and sealing ordinances.
But that is a long ways from the full celestial law. When we are baptized, we do even receive the fullness of the telestial law, much less the full celestial law. We start at the bottom rung. You can enjoy the gift of the Holy Ghost as soon as your are baptized. You are living the law, and can receive the blessing. But you probably didn’t receive the ministering of angels, or commune with the general assembly and church of the firstborn as soon as you were sealed or endowed. Nor did I. We have a long ways to go to climb our ladder and the full course won’t be finished in mortality. We just press forward along the strait and narrow path, knowing that is the correct route to our desired destination, and with a particular mind toward saving all we can.
As long as we have endured to the end, pressing forward, we expect that we will be able to continue our course in the spirit world And there is much of this course that we may receive in mortality, or there would be no point in the Lord giving us scriptures like this one:
D&C 107: 18 The power and authority of the higher, or Melchizedek Priesthood, is to hold the keys of all the spiritual blessings of the church—
So lets us fill this path out some more. As we continue to progress, we receive more and more of the telestial law. Angels and terrestrial beings minister to us so we can live up to their standard and receive a greater measure of the Holy Ghost. They give us more and more of the telestial law (by covenant) until we have the fullness.
Continuing in this path, eventually we will come to the point where we are ready to receive a terrestrial law. When we are ready to receive a terrestrial law, then we are also ready to begin receiving the same spiritual benefits as those who live in the terrestrial kingdom. We will be able to receive the presence of the Son, but not the fullness of the Father.
D&C 93: 16 And I, John, bear record that he received a fulness of the glory of the Father;
19 I give unto you these sayings that you may understand and know how to worship, and know what you worship, that you may come unto the Father in my name, and in due time receive of his fulness.
The terms don’t change between mortality and the resurrection. After the resurrection those who are living a celestial law can receive all that the father has. Those who are living a terrestrial law can receive of the presence of the Son, but they are not able, from living a terrestrial law alone, to receive all that the Father has. The celestial can minister to the terrestrial. Those living a telestial law receive the Holy Ghost, and to that end they are ministered to by angels and by the terrestrial.
And it is the same in this life. We see the same thing described in this life in Moroni 7, even if in looser terms.
We see angels minister to those in the telestial so they can receive the Holy Ghost. We also see there are some who can begin to enjoy the presence of the son. (And why? Because they have progressed to the point where they are living a terrestrial law and can therefore begin to enjoy precisely the same spiritual blessings those in a terrestrial kingdom enjoy.)
Moroni 7:22 For behold, God knowing all things, being from everlasting to everlasting, behold, he sent angels to minister unto the children of men, to make manifest concerning the coming of Christ; and in Christ there should come every good thing.
23 And God also declared unto prophets, by his own mouth, that Christ should come.
30 For behold, [angels] are subject unto him, to minister according to the word of his command, showing themselves unto them of strong faith and a firm mind in every form of godliness.
31 And the office of their ministry is to call men unto repentance, and to fulfil and to do the work of the covenants of the Father, which he hath made unto the children of men, to prepare the way among the children of men, by declaring the word of Christ unto the chosen vessels of the Lord, that they may bear testimony of him.
32 And by so doing, the Lord God prepareth the way that the residue of men may have faith in Christ, that the Holy Ghost may have place in their hearts, according to the power thereof; and after this manner bringeth to pass the Father, the covenants which he hath made unto the children of men.