Mormon also added a metaphor of his own in verse 11 to clarify his point and move forward into the next topic. He pointed out that “a bitter fountain cannot bring forth good water, neither can a good fountain bring forth bitter water, wherefore a man being a servant of the Devil cannot follow Christ and if he follow Christ he cannot be a servant of the devil.” That statement is related to a passage in the Sermon at the Temple in 3 Nephi 13:24: “Ye cannot serve God and Mammon.” Mormon’s people could not sit on the fence in this world. They needed to be soldiers, following Mormon, living righteously, and trying to fight the war. They didn’t have the luxury of choosing their lifestyle. However, they could choose how they responded to their circumstances. They could either face their challenges with the Savior or without him.
>Matthew L. Bowen, “‘That Which They Most Desired’:The Waters of Mormon, Baptism, the Love of God, and the Bitter Fountain,” Interpreter: A Journal of Latter-day Saint Faith and Scholarship 39 (2020): 261–298.