The word "healthy" here is a dead metaphor that means to be firm and unwavering. The abstract nouns "faith," "love," and "perseverance" can be stated as verbs. Alternate translation: "and they must firmly believe the true teachings about God, truly love others, and continually serve God even when things are difficult" (See: [[rc://en/ta/man/jit/figs-metaphor]] and [[rc://en/ta/man/jit/figs-abstractnouns]])