Luke 9:27 says “Truly I tell you, some who are standing here will not taste death before they see the kingdom of God.” If we read the Bible straightforwardly, who standing before Jesus in that moment did not taste death?
In Matthew, Mark, and Luke, this statement is made right before the transfiguration. Peter, James, and John got to see the kingdom (which can be translated “royal splendor”) when Jesus was transfigured before them.