"I will not" can be fully expressed as "I will not fall away." The phrase "not fall away" is a double negative and carries a positive meaning. This can be expressed in the positive if needed. Alternate translation: "Even if everyone else leaves you, I will stay with you" (See: [[rc://en/ta/man/translate/figs-ellipsis]] and [[rc://en/ta/man/translate/figs-doublenegatives]])