As a Christian I always found Life of brian hilarious. And yes, it is because it is not making fun of Jesus. It is making fun of his followers.
The thrown sandal scene is comedy gold.
It took me quite a while to realize that monty python were not making fun of Christ or christianity. They were making fun of people being kinda nutty in WHY they believed what they believe.
I think you are being naive. They don’t like Christians, and they don’t like Christianity.
I was sitting in church one day in the sound room at the end of the sanctuary and the pastor said one day that we should follow him just because he was showing the path.
I said to myself, “But the shoe is the sign.”
A friend sitting on front of me turned around and said:
“Cast off the shoe and follow the gourd.”
We both had a chuckle on it and could not hear anything else after that without hearing a reference to that movie.
Still makes me laugh.