Mosiah 27:26 - 27:30
Mosiah 27:26 And thus they become new creatures; and unless they do this, they can in nowise inherit the kingdom of God.
As a result of this close association of son to father, they became different people. They become more oriented to being concerned for other than themselves which makes them fit to be in a kingdom where that is the main motivation of all who live there.
[One can only wonder what it would be like to have everyone around you concerned and working for your welfare. Seeing that you had all you needed at the moment to develop your talents and abilities and you were doing the same to others. Couple this with not having to spend part of your efforts in providing for your mortal needs and you have a loving and caring environment. You lift me and I lift you and we all rise together. Selfishness is done away with. One’s joy comes only when others succeed whether through your efforts or other’s efforts on their behave. In fact the only thing on your mind is everyone succeeding around you.]
Mosiah 27:27 I say unto you, unless this be the case, they must be cast off; and this I know, because I was like to be cast off.
And unless they thus become so oriented to selflessness, they will not like the kingdom of heaven and as a result will not like it there and wish to be somewhere else. This self judgment will then cause the Father to send them to a place they feel more comfortable in.
Mosiah 27:28 Nevertheless, after wading through much tribulation, repenting nigh unto death, the Lord in mercy hath seen fit to snatch me out of an everlasting burning, and I am born of God.
But as far as Alma Jr. is concerned, he has been to hell and back while in his comatose state going through a sore repentance process. He is now ready to start his service to his fellow men rather than trying to destroy the Church.
Mosiah 27:29 My soul hath been redeemed from the gall of bitterness and bonds of iniquity. I was in the darkest abyss; but now I behold the marvelous light of God. My soul was racked with eternal torment; but I am snatched, and my soul is pained no more.
His experience while in this state was exactly like if he had been actually consigned to hell as in the final judgment. However, he was shown a way out and took it. He was troubled by an intensely guilty conscience, but by the grace of God he was able to clear up his conscience and feel he was forgiven of his transgressions.
Mosiah 27:30 I rejected my Redeemer, and denied that which had been spoken of by our fathers; but now that they may foresee that he will come, and that he remembereth every creature of his creating, he will make himself manifest unto all.
He now knew that he had rejected the Lord which he had been taught about by his father and others all his life. He now knew that the Lord would come to earth and through the atonement he would experience all the trials and joys of mortality so as to know each of us intimately. This will allow Him to show unto us individually that He cares for each of us and will show Himself in due time to each of us on a one on one bases.