Indeed, any of us who have desires to serve God are called to the work. (See Doctrine and Covenants 4:3)
So that is the real barrier that prevents us all from receiving this calling: we must not have a true desire to serve God. Sad as it is, too many mundane things get in the way every day.
Even worthy goals prevent us from going out to talk to our neighbors, and some of those goals might even be more important. For example, teaching the gospel in my own home is a very worthy goal. If I'm not teaching and living the gospel in my own home, I won't have a large measure of the Spirit with me if I go out and try to teach the gospel to my neighbors. However, that could easily be used as an excuse for not going out to do the work. Many of the early brethren were called to leave their wives and families to go and preach the gospel abroad. Surely their families were blessed greatly because of their service. Teaching others is one of the most excellent ways to show our own families the importance the gospel has in our lives.
What other obstacles do we have from being called to the work? Anything in our lives that lessens our desire to serve God prevents us from receiving the call. And yet, many are called. Many do have a desire to serve God. Many have covenanted to serve God every day of their lives, even to give up their lives in the service of God, if necessary. The desire is there, the spirit is willing.
But the flesh is weak, few are chosen. What is it that those who are called to serve are being chosen for by the Lord? Simply to do that for which they have been called.
There has been a day of calling, but the time has come for a day of choosing; and let those be chosen that are worthy. (D&C 105:35)
It is our worthiness that determines whether we are chosen to serve:
Behold, thou art Joseph, and thou wast chosen to do the work of the Lord, but because of transgression, if thou art not aware thou wilt fall.
But remember, God is merciful; therefore, repent of that which thou hast done which is contrary to the commandment which I gave you, and thou art still chosen, and art again called to the work; (D&C 3:9-10)
That is why many are called, but few are chosen (D&C 121:34). Our hearts are set too much upon the things of this world. We also have the tendency to aspire to the honors of men, rather than seek for the honor of God by giving the honor to Him. Those who are chosen have the desire to do God's will, not their own. How many times do we worry what others may think. Isn't that one of the biggest excuses that we come up with for not doing missionary work? We are afraid of man, when we should fear God.
What do we do to be able to overcome the tendency of the natural man? God is willing and waiting to help us. He wants to bless His children. What is the over-encompassing reason that we are commanded to build temples and receive the ordinances thereof and why do we receive the priesthood? Their purpose is one: to enable God's children to be blessed and be able to once again return to His presence.
Yea, verily I say unto you, I gave unto you a commandment that you should build a house, in the which house I design to endow those whom I have chosen with power from on high; D&C 95:8
The marvelous thing about the temple and the sealing power of the priesthood is that it confirms that God is no respecter of persons. He wants all of His children to have the opportunity to choose for themselves and be able to return to His presence. Indeed, He wants to bless His children with all that He has. Those of us whe are parents that love our children get a good glimpse into understanding the nature of this love.
What is meant by the sealing power of the priesthood? Whenever the priesthood has been given to man in its fulness, God has promised that "whatsoever thou shalt bind on earth shall be bound in heaven" (Matt 18:18, Hel. 10:7, D&C 124:93, 132:46). The power is referred to in conjunction with the "keys of the kingdom of heaven" (Matt. 16:19).
The sealing power of the priesthood has been restored on earth so that all of God's children can receive the choice whether to accept His plan for them. If we choose to follow His will for us, He asks us to make covenants with Him that we will keep His commandments and that He will bless us. These covenants are made when priesthood ordinances are bestowed. Baptism has its associated covenants. Men who receive the priesthood make covenants as they receive it. The other ordinances of the temple (endowments and sealings) also have their associated covenants.
We must prepare ourselves to keep the covenants that we enter into. That is why only worthy members of the church who are keeping the commandments can attend the temple.
God would not be just if he allowed some children the ability to receive exaltation and didn't give the oportunity to others. Those who don't have the opportunity to make these covenants in their lifetime are given the opportunity to accept the ordinances that are performed for them vicariously. In this way, God is completely fair to all of His children. He ensures that all of us will have our agency to choose whether we will accept His will and enter into a covenant with Him to do His will and thereby be blessed to return to His presence and receive all that He has. Someone who dies without receiving the gospel can receive it in the post-mortal spirit world. Once their temple ordinances are performed, they can choose to accept them.
Vicarious ordinances are not something new. We all have had the greatest vicarious sacrifice of all performed for us by our saviour Jesus Christ. It is when we accept His sacrifice through baptism that we are allowed to enter into the path that returns to our Father's presence.
What greater cause is there for motivation to share the restored gospel? When we consider that we are sinners and that we could never hope to amount to anything without the atonement of Jesus Christ, and when we consider that our Father sacrificed His son and that Jesus gave his life freely for us because of their unconditional love for each one of us, you realize how much love and desire they have for all of us. Recognizing our own reliance on God for all that we have, and for every blessing that we may receive, causes us to feel empathy for our brothers and sisters. We cannot accept the mercy given to us without recognizing the need for us to extend mercy to all those around us.
When we learn and remember that God's plan and purpose for us as His children is to have us grow to become like Him, that his commandments are the path laid down to help us receive this joyful outcome, and that His greatest commandments are to love the Lord thy God above all else, and to love our neighbor as ourselves, we realize that it is through sharing the gospel with our brothers and sisters that we can receive the greatest joy, the greatest opportunity for growth, and the most blessings- in this life and into eternity. (See Matt. 22: 36-40, Moses 1:39).
I pray that we may have the desire to be called and live worthy to be chosen to do God's work. It is all about love.