Thinking Christianity as a poison seems to be a atheist belief. Only the atheist who are against all religions conclude with these unrealistic statements.
Your distain of Christianity is in my opinion blinding your objectivity. Yes sins have been committed in the name of Christianity. Human beings often embrace evil with or without religion. God teaches us how to improve if we listen.
The Catholic church is one of the many human institutions built to honor and serve God. All such institutions are guaranteed to have at best a pale and shallow understanding of God. If you are Catholic you believe the church is the best of these institutions with the most accurate understanding of God.
The Catholic Church is far from perfect. It has many flaws and many crimes have been committed in its name. At the same time it has contributed greatly to human progress.
The claim that science had advanced despite religion completely overlooks the fundamental relationship between God, progress, and freedom. The only reason we have come as far as we have is due to the organizational superstructure provided by the worship of God.
If you are interested in the logic behind this I would refer you to the following posts: