Some have been troubled by the question why both the Bible and the Book of Mormon say that many of the graves were opened and many of the Saints came forth, rather than saying that all the Saints were resurrected at this time. The answer to this question must involve the teaching of the gospel in the spirit world. While his body lay in the tomb, Christ visited the faithful spirits in prison, meaning those in the spirit world (see D&C 45:17; D&C 138:50), and issued calls from among their number for them to commence the teaching of the gospel in the world of the spirits (see D&C 138:30-31). Thus it may be that among the righteous all received a call to labor as messengers of the Lord, some in the world of the spirits and the others among mortals. Those laboring among the spirits presumably were resurrected upon the completion of their mission in the spirit world.