The first five questions asked the audience if they could remember God’s great acts for his people, their heritage, and God’s deliverance. I like the way Alma asked these questions in a kind of lawyerly way, with some nice qualifiers. He didn’t only ask if they had remembered; he asked if they had "sufficiently remembered."
Have we remembered enough? Have we remembered sufficiently the captivity, or the problems that Joseph Smith faced, or that our ancestors were plagued with as they came to settle this valley?
In verse 9, he asked, "Were the bands of death broken, and the chains of hell which encircled your fathers about, were they loosed?" Do you think God acted in their lives? Do we even know enough about our ancestors, about our heritage, to answer that question?
Each of the first three questions begins with the phrase, "Have you sufficiently retained in remembrance?". In Hebrew, the word for remember is zkhr, and it does not just mean to remember in the sense of recalling. It means to remember in the sense of obeying. When your mother said, "Remember what I have taught you," she wasn’t asking if you could pass a recall test. When she said "Remember it," she meant, "Do what I have taught you." And that is what we see in the Book of Mormon. The word remember does not just mean to think about it, but to do it.
In the fourth question, Alma asked, "Were your fathers destroyed?" They were not. They were delivered from captivity. Perhaps Alma’s people were worried about being destroyed; Zarahemla was not impervious to attack. Just a few years before this speech there had been a bloody civil war. The Lamanites were just now beginning to put pressure on the Nephites again. Perhaps Alma sought to put his people’s minds at peace so that they knew that they could rely on God.
Book of Mormon Central, "Why Does Abinadi Use the Phrase ‘the Bands of Death’? (Mosiah 15:8)," KnoWhy 93 (May 5, 2016).
Louis Midgley, "The Ways of Remembrance," in Rediscovering the Book of Mormon: Insights You May Have Missed Before, ed. John L. Sorenson and Melvin J. Thorne (Salt Lake City and Provo, UT: Deseret Book and FARMS, 1991), 168–176.
Louis Midgley, "’O Man, Remember, and Perish Not’ (Mosiah 4:30)," in Reexploring the Book of Mormon: A Decade of New Research, ed. John W. Welch (Salt Lake City and Provo, UT: Deseret Book and FARMS, 1992), 127–129.