3 And now, O my son Helaman, behold, thou art in thy youth, and therefore, I beseech of thee that thou wilt hear my words and learn of me; for I do know that whosoever shall put their trust in God shall be supported in their trials, and their troubles, and their afflictions, and shall be lifted up at the last day.
Alma’s words are the pleading words of every parent who has hoped that his or her children could avoid the painful mistakes that they made in youth. Alma hopes that by sharing his testimony and his conversion experience he can help his children avoid anguish and regret. 

Alma in his youth rebelled despite his righteous father. So he knows that this won’t always work. Children have their agency. They can and must make their own decisions and their own mistakes.

But Alma understood something that we can learn as parents. He understood that our children need not only be taught facts and rules, but also that they must be given a sense of why those rules matter. By sharing his experience, Alma has helped his children in a vicarious fashion experience what he experienced. And he has clearly given them a warning and a promise. If they follow God, they will be blessed and if they rebel they will be cursed.