Jesus said he was not there to cast away the old laws, meaning the 10 Commandments, but he was telling them it was okay to leave behind the ritual purity laws that the early Israelites had committed themselves to following.

I would say that many bad people have tried to justify their bad actions in the name of their faith or religion, but I do not think that it makes the actions of those individuals something that is okay.

Some early Christians were eager to add a few extra parts to the Bible for instance that justified the patriarchy in the church. They attributed a few sections as being directly from Paul, but they were written by some of the other early Christians instead but attributed to Paul to give them weight.

The issue is that so many people do not follow Jesus’ example whatsoever. They look at Jesus, see what Jesus did was great, but then do not seek to emulate Jesus or his teachings.