These four expressions all mean the same thing and strongly emphasize that they are not to be afraid. If your language does not have four ways to express this concept, you may use less than four. (See: [[rc://en/ta/man/jit/figs-parallelism]])
Here "hearts" represents people's courage. For a heart to faint is an idiom that means "Do not be afraid." (See: [[rc://en/ta/man/jit/figs-metonymy]] and [[rc://en/ta/man/jit/figs-idiom]])