The Book of Mormon teaches that the fall of Adam was no surprise to the Lord, but was actually expected according to the fore-knowledge of God, and was part of his original plan (see 2 Nephi 2:22-25). In 2 Nephi 2:24-26 we find that, "all things have been done in the wisdom of Him who knoweth all things. Adam fell that men might be; and men are that they might have joy. And the Messiah cometh in the fulness of time, that he may redeem the children of men from the fall."
Richardson, Richardson and Bentley write that many churches teach that the fall of Adam was a surprise to God--a terrible blunder that disrupted his plans and sent him searching for a solution of redemption for all mankind. Some of these churches are critical of the LDS Church for its stand on the Fall. It is ironic that Bible-believing Christians would believe notions which are contrary to the Bible. The Bible teaches that as the fall was anticipated, likewise, the atonement of Christ was planned from the beginning. In Revelation 13:8, the apostle John speaks of the "Lamb slain before the foundation of the world." This means that the atonement was anticipated even before the world was created. Clearly, if the atonement was anticipated, the reason for the atonement or the fall was also anticipated.
It is interesting that according to ancient texts, the early Christians in the Old World looked upon the fall of Adam as a great blessing. If it was to be considered by some to be iniquity, they preferred to call it "blessed iniquity." (Seaich, Ancient Texts and Mormonism, p. 41.) [Allen H. Richardson, David E. Richardson and Anthony E. Bentley, 1000 Evidences for the Church of Jesus Christ of Latter-day Saints: Part Two-A Voice from the Dust: 500 Evidences in Support of the Book of Mormon, p. 40]