D&C 134:12

“We believe it just to preach the gospel to the nations of the earth, and warn the righteous to save themselves from the corruption of the world; but we do not believe it right to interfere with bond-servants, neither preach the gospel to, nor baptize them contrary to the will and wish of their masters, nor to meddle with or influence them in the least to cause them to be dissatisfied with their situations in this life, thereby jeopardizing the lives of men; such interference we believe to be unlawful and unjust, and dangerous to the peace of every government allowing human beings to be held in servitude.”

D&C 134:12