Alma 12:28-30 - "...it was expedient that man should know concerning the things whereof [God] had appointed unto them; Therefore he sent angels to converse with them, who caused men to behold of his glory...therefore God conversed with men, and made known unto them the plan of redemption, which had been prepared from the foundation of the world; and this he made known unto them according to their faith and repentance and their holy works." God's plan has never been a secret. Not since the beginning of time. He is a loving and even I would say a doting God that wants salvation for all his children. Salvation, however, HAD TO BE conditional! No unclean thing can enter into his presence. If you think of the truly evil people who have existed on this earth with no thought of repentance, and think that in the end they will be dwelling in happiness in heaven, the idea is almost ludicrous. If those people don't make it to heaven, then, doesn't it make sense that there is SOME standard established? If, then, there is such a standard, wouldn't it be prudent for us to figure out what it is and then strive to far surpass it, just to be safe? Makes sense to me... "[glad tidings of the plan of salvation] are made known unto us in plain terms, that we may understand, that we cannot err; and this because of our being wanderers in a strange land; therefore, we are thus highly favored, for we have these glad tidings declared unto us in all parts of our vineyard." (Alma 13:23)
Alma 41:7 [The righteous] are they that are redeemed of the Lord; yea, these are they that are taken out, that are delivered from that endless night of darkness; and thus they stand or fall; for behold, they are their own judges, whether to do god or do evil." In the end when we are brought to judgment, we will not be able to lie even unto ourselves. we will know of our state of purity at that tribunal.
Alma 42:16 Now, repentance could not come unto men except there was a punishment, which also was eternal as the life of the soul should be, affixed opposite to the plan of happiness, which was as eternal also as the life of the soul." It is a little daunting to think of this fact, but we, as intelligences, have always existed, thus we will continue to exist into eternity, not in the body as we have it now, but as eternal beings. The destruction of that intelligence is not possible, for man, or for God.
Alma 42:27 ...whosoever will come may come and partake of the waters of life freely; and whosoever will not come the same is not compelled to come; but in the last day it shall be restored unto him according to his deeds." Thus we always have the choice of which master we will heed. But in the end, if we have not chosen the Savior, we may as well have chosen the devil."