Judgment comes on the children of men based on that degree of light and knowledge that they were privileged to receive during mortality. He who sins against the greater light shall receive the greater condemnation (DC 82:3). Missionaries think of themselves as the messengers of salvation. However, when one becomes a member of the church and then rejects the Lord, the convert has only brought condemnation down upon their own heads. If the new converts can't be retained, they are actually worse off than if they never heard the message of the gospel. This means that retention of new converts is a great responsibility. It also encourages missionaries to baptize only those who are ready for baptism as explained in DC 20:37. The individual must:
Peter spoke of this same group of people as follows:
'For if after they have escaped the pollutions of the world through the knowledge of the Lord and Saviour Jesus Christ, they are again entangled therein, and overcome, the latter end is worse with them than the beginning.
For it had been better for them not to have known the way of righteousness, than, after they have known it, to turn from the holy commandment delivered unto them.
But it is happened unto them according to the true proverb, The dog is turned to his own vomit again; and the sow that was washed to her wallowing in the mire.
Interestingly, the scriptures speak of three different warnings which all use similar language. First, 2 Nephi 31:14 and 2 Pet 2:21, speak of those who at first accept the gospel and then turn away, it would have been better for them if they had never known the gospel. Second, DC 54:5, DC 121:22, and Matt 18:6 (Mark 9:42, Lu 17:2) describe the fate of those guilty of certain sins as follows, it would be better for them to be drowned in the depth of the sea. Third, DC 76:32-35 and 3 Nephi 28:34-5 speak of those who reject the testimony of the Holy Ghost and deny Christ at the last day. Of them it says that it would be better for them if they had not been born.