"For this people’s heart is waxed gross, and their ears are dull of hearing, and their eyes they have closed; lest at any time they should see with their eyes, and hear with their ears, and should understand with their heart, and should be converted, and I should heal them. (New Testament, Matthew 13:15)"
This passage of scripture seems to suggest that Christ taught in parables or a bit cryptically to purposely convince and convert some but not convert and convince others. This scripture is used by Calvinist to justify the false doctrine of predestination. If God loves everyone, why would Christ suggest that He would purposely seek to save some but not others?
In the pre-mortal life in heaven, God clearly explained the logic and reasons for everything. Many people believed and choose to follow God's plan not necessarily because they loved it, but because they could not disbelieve it. Some Book of Mormon prophets taught with this kind of power.
"And it came to pass that they were angry with him, even because he had greater power than they, for it were not possible that they could disbelieve his words, for so great was his faith on the Lord Jesus Christ that angels did minister unto him daily. (Book of Mormon, 3 Nephi 7:18)"
This life is a test to find out who really loves God and who really loves truth. So, God doesn't necessarily "spell eveything out" so-to-speak. God allows there to be reasons for and against belief. The reasons for belief are much, much better but nevertheless there are reasons both for and against (oposition in all thing). This goes for belief in Joseph Smith or the Book of Mormon or Christ or anything.
Those who really love God and love the truth will hear the reasons for belief and will truely desire that these things be true. Those who love God and His way of doing things will cleave unto God, and cleave unto truth and seek, study, ponder, and pray and then receive a confirmation by the Holy Ghost. Those who never really loved the truth and doing thing God's way will find plenty of reason's not to believe and continue on living their life the way they wish it.
God really is no respecter of persons. God is inviting all people to come unto Christ and be perfected in Him, but God calls in such a way that only those who truely love Him and love the truth will hear His voice. All are invited but God is separating out the valiant followers of Christ from the average but honorable "fair-weather fans".