What was the story behind the Knights Templar being outlawed by the Catholic Church?

I was reading a lot about the Knights Templar, and I couldn't make sense of it. This order was created to help Christians get to Jerusalem without being molested, but the order wasn't specified to Catholics, it was to Christians. And it certainly helped a lot of people going to Jerusalem, despite being a military order, because they promised safety to all Christians, despite the fact that the Catholic Church, for example, saw Protestants as heretics. I honestly can't make sense of how the order was outlawed by the very people that created it in the first place, the Catholic Church.