The rubbish that any religion is as good as any other denies the Godhead of the Blessed Trinity and the reality of Christ’s formation of His Catholic Church is unable to discern truth from error, and thus wallows in an anything goes euphoria.
Salvation – Extra ecclesia nulla salus.
“Those who, through no fault of their own, do not know the Gospel of Christ or His Church, but who nevertheless seek God with a sincere heart, and, moved by grace, try in their actions to do His will as they know it through the dictates of their conscience – these too may achieve eternal salvation.”
Popes knew this from St Clement through Pius IX to John Paul II and Benedict XVI.
Pope St Clement I, wrote in about 95 A.D. to the Church in Corinth: “Those who repented for their sins, appeased God in praying and received salvation, even though they were aliens to God.” Catholic Apologetics Today, 1986, Fr William G Most, p 145].
From Pope Pius IX
“By Faith it is to be firmly held that outside the Apostolic Roman Church none can achieve salvation. This is the only ark of salvation. He who does not enter into it will perish in the flood. Nevertheless, equally certainly it is to be held that those who suffer from invincible ignorance of the true religion, are not for this reason guilty in the eyes of the Lord. Now, then, who could presume in himself an ability to set the boundaries of such ignorance, taking into consideration the natural differences of peoples, land, native talents, and so many other factors” (Singulari Quidem, 1863 A.D.). Hence, Pius IX distinguished between those who have knowledge of the Church and Her divine foundation, and those who have no such knowledge due to a number of mitigating circumstances.
[My emphasis].