The Pope is a man appointed by God to lead the Catholic Church and has great love in his heart for the common man and those that have been marginalized and disenfranchised
Mother Teresa was kind and did a lot of great things for people, but it would all count for nothing if she died without Jesus.... at the same time I believe God may have brought some relief to some people as a result, according to His will. The scriptures even say that He uses one evil to wipe out another evil. Remember the delusion in the end times, how God will send this delusion. All part of His plan.
The pope does preach a different gospel though. Without even going into everything (which is for another thread), the pope has the title of "vicar of Christ" which basically that worldly system grants to the pope the roles that Christ said would belong to the Holy Spirit.