“Lift Up Your Heart and Rejoice, for the Hour of Your Mission Is Come”
Doctrine and Covenants 31:1–6
1 Thomas, my son, blessed are you because of your faith in my work.
2 Behold, you have had many afflictions because of your family; nevertheless, I will bless you and your family, yea, your little ones; and the day cometh that they will believe and know the truth and be one with you in my church.
3 Lift up your heart and rejoice, for the hour of your mission is come; and your tongue shall be loosed, and you shall declare glad tidings of great joy unto this generation.
4 You shall declare the things which have been revealed to my servant, Joseph Smith, Jun. You shall begin to preach from this time forth, yea, to reap in the field which is white already to be burned.
5 Therefore, thrust in your sickle with all your soul, and your sins are forgiven you, and you shall be laden with sheaves upon your back, for the laborer is worthy of his hire. Wherefore, your family shall live.
6 Behold, verily I say unto you, go from them only for a little time, and declare my word, and I will prepare a place for them.
President Joseph Fielding Smith wrote:
“At this time [September 1830] Thomas B. Marsh joined the Church. He had been a member of the Methodist Church, but when comparing their doctrines with the scriptures, he failed to make them agree, so he withdrew from that sect and sought some other organization teaching the doctrines as he felt he discovered them in the Bible. He predicted that such an organization would arise. He was moved by the Spirit of the Lord to move west. His home was in Massachusetts. He met Martin Harris while the Book of Mormon was being printed and remained with him for several days and then returned to his home in Boston, but kept up correspondence with the Prophet and Oliver Cowdery and upon learning of the organization of the Church, he moved to Palmyra in September 1830 and was baptized by David Whitmer and a few days later was ordained an elder by Oliver Cowdery. The Lord told Thomas B. Marsh that he had had many afflictions because of his family, ‘yea, your little ones,’ but he was informed that the day would come when they would know the truth. He was informed that the hour of his mission had come, indicating that he was to be called to declare the things which had been revealed to the Prophet. He was to labor with his might and reap, for the field was ‘white already to be burned.’ He was to be patient in affliction and to revile not against those that revile. He was to be a physician to the Church, but not unto the world, for they would not receive him. He was cautioned against temptation and if he would be faithful to the end he would receive his reward. Thomas B. Marsh was a man of ability and could have been very useful in the Church, but he failed when persecution became strong and did not endure in his afflictions. When the opposition to the Church became severe and his feelings were disturbed, he left the Church and spoke in an evil and bitter spirit against the Prophet and the Church, thus encouraging our enemies. The falsehoods which he uttered have been used by the enemies of the Church to this day. Later in his life, however, when he was a broken man, he returned to the Church and, standing before the congregation, called upon them to look upon him as an object of apostasy, and he warned the members to avoid a course which would bring them to a similar condition. [See John Taylor, The Gospel Kingdom, pp. 185–89.]”
(Church History and Modern Revelation, 2 vols. , 1:147–48.)