What is the worst sin someone can commit?

Falsely accuse someone that they end up in prison for a very long time.

Genocide, probably.

Crimes against children are the worst crimes.

Sin doesn't exist.

Child abuse, animal abuse, domestic abuse.

The sin of not believing in God. Believe it or not we are all going to meet Him in person one day not to far away. If one doesn't believe he is a fool and will be cast into hell forever, not a place anyone should want to end up at, The choice is our's believe or not

Well honestly if you commit one sin you are guilty of breaking the whole law
..in human eyes we put a degree to sin but all sins are harmful I can't say that I sin less than you All of us are guilty inbreaking the law. It is only by mercy

Got to be disbelief, right? Most Christians will say it's never too late for anyone to be saved, but only if they believe.

THE MORTAL SIN OF KNOWINGLY NOT CONFESSING THEIR SINS BEFORE DEATH.

Not deciding to obey all of Jesus' sayings .

Rejection of the truth of Jesus Christ.

The sin of unbelief. For once someone does not believe in God and His Christ, they make themselves a god, where they serve themselves.

Deceiving a third of the world's population, but Paul has managed to do exactly that...

SUICIDE. It's the only sin you can't repent of, after committing it.

Abortion........

abortion is a hot topic right now