For me, two passages- one from the Bible, one from Vatican II- solve this problem.
John said to Him, “Teacher, we saw someone casting out demons in Your name, and we tried to prevent him because he was not following us.” But Jesus said, “Do not hinder him, for there is no one who will perform a miracle in My name, and be able soon afterward to speak evil of Me."
Second Vatican Council- Decree on Ecumenism - Unitatis Redintegratio
“The children who are born into these Communities and who grow up believing in Christ cannot be accused of the sin involved in the separation, and the Catholic Church embraces upon them as brothers, with respect and affection. For men who believe in Christ and have been truly baptized are in communion with the Catholic Church even though this communion is imperfect. The differences that exist in varying degrees between them and the Catholic Church-whether in doctrine and sometimes in discipline, or concerning the structure of the Church-do indeed create many obstacles, sometimes serious ones, to full ecclesiastical communion. The ecumenical movement is striving to overcome these obstacles. But even in spite of them it remains true that all who have been justified by faith in Baptism are members of Christ’s body,(21) and have a right to be called Christian, and so are correctly accepted as brothers by the children of the Catholic Church.(22)”
In this modern age, you won’t find the Pope, Cardinals, bishops, and even priests going out and evangelizing Protestants, Orthodox, or other non-Roman Catholic Christians. The spirit of the Counter-Reformation is deceased; it does not exist now.
Our differences as Christians no longer matter, praise God.