If the pope says all religions are a path to God, why evangelize, and how did this idea arise?

This is not new; the liberal movement started right after Gregory XVI took Galileo off the Index of Forbidden Books in 1835. The mentality that developed was: if the Church finally admitted she was wrong about geocentrism, then she is probably wrong about her stand against evolution and against creation ex nihilo, so we no longer have to read the Bible literally. That is the gas for the car that has been running for the last 200 years: everything previous was thrown away, and it had to be based on science, with everything natural, no miracles, no Earth in the center. John Paul II said this himself in his 1992 speech to the Pontifical Academy of Science, that the earlier popes felt under compulsion to read Scripture literally, but now that we know Galileo was right, we do not have to. Yet literal interpretation was the legacy of Catholicism; it is how we got the Eucharist from 'this is my body,' because the Church took the words at face value. Once you throw out the literal interpretation of Scripture because everyone thinks the Earth moves and Scripture got one thing wrong, then it can be wrong about another and another, and you end up exactly where the pope is today, saying all religions are a path to God without qualification, which means he is not preaching the gospel. That is why the geocentric issue is so important: it is one ball of wax, like a sweater that unravels once you pull the loose thread.