D&C 1:4-5, 30; 65; 109:72-74; 123:12
The Doctrine and Covenants is an invitation to all people everywhere to come unto Christ. In the revelations of this book “one hears the tender but firm voice of the Lord Jesus Christ,” inviting all to come unto Him “preparatory to his second coming.” 
The purpose of missionary work is to bring souls to Jesus Christ.
One of the worrisome things about much of what is called missionary work in the Church is our lack of determination to do this. I’m not talking about the organized missionary effort, unprecedented in all the dispensations in its scope and success. I’m referring instead to the work we should all be doing every day-for we are all “on a mission” in this world by virtue of being baptized. Every soul who takes the name of Christ is clearly under the obligation to share the gospel. The Lord has said, “The voice of warning shall be unto all people, by the mouths of my disciples, whom I have chosen in these last days.” “It becometh every man who has been warned to warn his neighbor.” Every disciple of Christ has this obligation. What we often forget, however, is the second half of the Lord’s exhortation: “And they shall go forth and none shall stay them, for I the Lord have commanded them.” 
Too often we allow ourselves to be “stayed” instead of “going forth” to do the work of bringing souls to Christ. We are fatally distracted from our missionary responsibility by our fears and by the cares of the world. We are lax in our study of the Gospel and in the cultivation of our own testimonies. We think ourselves weak and powerless. We fail to exercise the great power that the Lord gives to those who follow his commandments: the power to bring our brothers and sisters out of darkness and into his marvelous light and warm embrace.
“And also those to whom these commandments [are] given, might have power to lay the foundation of this church, and to bring it forth out of obscurity and out of darkness.” 
When we tell people that they have a Savior who loves them, the Spirit invests that testimony with power. When they hear that the Prophet Joseph was sent by God to bring them this message, they feel the force of that witness. When they can tell that we in our turn love them, what a powerful influence it has on them.
Too often we fail to send this message and end up sending the wrong message instead. We argue about doctrines. We mistake some political position for the Gospel message. Or we fail to send any particular message at all. I think of home teaching visits where no testimony is borne. I think of Sunday School lessons where the Gospel of the Son of God is not taught. I think of so-called “motivational” talks in meetings that preach this or that virtue but give little attention to the name of Jesus Christ other than to invoke it at the end.
As disciples of Christ we are on a singular mission that requires our best efforts-to bring ourselves and our brothers and sisters back to Him. This is the broad and true meaning of the term “missionary work.” Too often we narrow the definition of “missionary work” to the great efforts of the full-time elders and sisters. But we are all engaged in the same work, whether in our homes or our Church callings or our communities.
That work consists of helping others to prepare to meet the Lord and to be “encircled eternally in the arms of his love.” 
“Hearken, and lo, a voice as of one sent down from on high . . . Prepare ye the way of the Lord, make his paths straight. . . . Yea, a voice crying-Prepare ye the way of the Lord, prepare ye the supper of the Lamb, make ready for the Bridegroom.” These commandments are the very essence of missionary work. We are to “prepare the way” by helping others to come to the “supper of the Lamb,” or the sacrament table. How do we do this? By “making the paths straight.” We cannot go at this work in a roundabout fashion. What people need is the straightforward teaching of the plain Gospel of Christ and the straightforward testimony of the love of our Savior.
How do we ensure that the Lord guides our efforts? He makes clear that if we pray seriously for it, for the softening of the hearts of the world, that guidance will come and the kingdom will move forward. “Call upon the Lord, that his kingdom may go forth upon the earth, that the inhabitants thereof may receive it, and be prepared for the days to come, in the which the Son of Man shall come down in heaven, clothed in the brightness of his glory, to meet the kingdom of God which is set up on the earth.” 
Additionally, the members of the Church must make sure that they keep the commandments faithfully so that they will have the power to bring others to Christ, “That thy church may come forth out of the wilderness of darkness, and shine forth fair as the moon, clear as the sun, and terrible as an army with banners.” This beautiful verse might be paraphrased this way: that the children of God might be brought out of the darkness of this telestial world, the Church members must qualify themselves to do so. They must “shine forth fair as the moon”-as pure and white as the moonlight-“clear as the sun”-as pure and purifying as the heat of the sun-and “terrible as an army with banners,” meaning as awe-inspiring as a great, united army marching under the flag of a unifying message.
To succeed in our mission, we need to be pure and at one with the Lord and with each other. Only if we fulfill these conditions can we exercise the “powers of heaven.” 
If we do so, we can have the confidence of a true disciple of Christ. We can have confidence that He will grant us the power we need to do His work.
“For there are many yet on the earth among all sects, parties, and denominations, who are blinded by the subtle craftiness of men, whereby they lie in wait to deceive, and who are only kept from the truth because they know not where to find it.”  Our task is to show them where to find the truth.
The day will come the Lord will unveil the heavens  and invite each of his disciples to come forward-one by one-and greet and embrace Him. On that day, we will want to be surrounded by as many as possible of our brothers and sisters, surrounded by those we have influenced in some way to come unto Him-our children, our family members, our ward or branch members, our friends, our neighbors-as many as we have touched with the power of our testimonies. If we do so, He will take us into his loving embrace and whisper to us, “Well done, thou good and faithful servant.”
 D&C Explanatory Introduction
 D&C 1:4-5; 88:81
 D&C 1:30
 2 Ne. 1:15
 D&C 65
 D&C 121:36
 D&C 123:12
 D&C 109:72-74