Slander and divisive speech is equivalent to psychological violence, which propels individuals and groups to physical violence.

Likewise, dividing spiritual communities inflicts spiritual damage, which has worse consequences since students can lose their faith in the teachings and especially in their own souls.

Also, slander is considered cannibalistic in Islam:

12 O you who believe! Shun much conjecture. Indeed, some conjecture is a sin. And do not spy upon one another, nor backbite one another. Would any of you desire to eat the dead flesh of his brother? You would abhor it. And reverence God. Truly God is Relenting, Merciful. —Qur’an 49

Thank you for your response. Unfortunately, that didn't quite answer my question. I do understand what you said about slander and divisive speech and the effects of them but I am having a hard time understanding the levels of sin and the gravity of their effects. If I slander somebody, it is psychological violence and it produces negative energy and can have negative effects on somebody or a group. If I physically kill somebody, their dead. So their are levels of negative karma. All are sins but some are less severe than others, right?