Oh, yes it does matter which religion we follow! Jesus Christ established the One True Church, that is, the Roman Catholic Church. To her He entrusted the Sacraments and the Full Deposit of Faith and Tradition. To foolishly claim "it doesn't matter" is to commit a sin against faith and against God who commands how He wishes to be worshiped. It trivializes and holds cheap the graces that are to be found in the Roman Catholic Church alone. Any one of us engaging in that sin would be held accountable for this sin against the First Commandment. It is reasonable to believe that such accountability is magnified many times for the Chief Shepherd of the Church.
Speaking of "earth day", here is a stamp that the Vatican released in its honor. Look closely. Do you detect anything that might suggest the Vatican's role in the Church? I can't detect one Crucifix on it.
But there is a religion being touted on that stamp, albeit implicitly: gaia-worship. It seems that according to the pope, "gaia-worship" is on a par with Catholicism. Any Catholic who truly believes that is engaging in heresy and endangering their immortal soul. Please wake up and go to Confession immediately.