If someone catalyzes good behavior on the part of others - he is guarded from sin (for it would be unfair for him to roast in Hell while his pupils savor Heaven).

But if someone leads others to behave negatively - he is prevented from repenting (for it would be unfair for him to savor Heaven while his pupils roast in Hell).

Moshe Rabeinu catalyzed good behaviors on the part of others...

Yeravam ben Nevat lead others to sin...