Helaman 16:15

Nevertheless, the people began to harden their hearts, all save it were the most believing part of them, both of the Nephites, and also of the Lamanites, and began to depend upon their own strength, and upon their own wisdom, saying:

But the people began to make their hearts hard. Except for those who believed most. This was true for both Nephites and Lamanites. They began to depend on their own strength. They depended on their own wisdom. They said:

Yet people hardened their hearts—all except the most faithful believers among both Nephites and Lamanites. They started relying on their own strength and wisdom, saying: