Today, Ecumenism and Inter-Religious Dialogue have become synonymous with the general line followed by the Pontiffs since Vatican II. Indeed, one could well say that nothing has been more straightforward than the Vatican policy of developing relations among religions. In these relations, there is no concern about the truth, and even less concern about bringing the followers of those false religions to the bosom of the Catholic Church in order to profess the unique true Faith. On the contrary, the conciliar Popes have virtually forbidden any effort to convert schismatics, heretics, Jews and pagans.
This position, however, is clearly opposed to Catholic Dogma and the Pontifical Ordinary Magisterium of the past. As an example of this constant teaching, we offer an excerpt from the Encyclical Singulari quidem, in which Pope Pius IX strongly condemned Ecumenism, then identified by the expression Religious Indifferentism.
John Paul II being blessed by a Shiva witchdoctor who worships devils...
Pope Pius IX
You well know, Beloved Sons and Venerable Brethren, that among the many deplorable evils which disturb and afflict principally the ecclesiastical and civil society, two stand out in our day and are justly considered to be the origin of the others.
In effect, you are aware of the innumerable and fatal damages which the terrible error of Indifferentism causes to Christian and civil society. It causes us to forget our duties to God in Whom we live and act and have our being. It causes us to lose our concern about our Holy Religion and destroys almost to the very foundation all law, justice, and virtue.
There is little difference between this most vile form of indifference and the demonic system of indifference between the different religions. According to this system, those who have strayed from the truth, who are enemies of the true Faith and forget their own salvation, and who teach contradictory beliefs which never had stable doctrine, admit no distinction among the different creeds. Rather, they make a pact with everyone, and defend that the haven of eternal salvation is open to the followers of all religions, whatever they might be. They do not care about the diversity of their doctrines as long as they agree to combat the one that is the unique truth.
You see, Beloved Sons and Venerable Brethen, how much vigilance is needed to keep the disease of this terrible evil from infecting and miserably killing your flocks. Do not cease to diligently defend your people against these pernicious errors.
(Encyclical Singulari quidem §§ 3-4)
Fr Hesse: Vatican II Ecumenism vs Catholic Dogma