Why Attempt to Convert Protestants?
Updated: Dec 10, 2021
By Luke Lancaster
Many Catholics think that attempting to convert our Protestant brothers and sisters into the fullness of truth within Catholicism is unimportant. Protestants love the Lord, they believe in the Resurrection of Jesus, and they hold to the inspiration of the Bible, so why make it a priority? The reason is because they are not FULLY brothers and sisters. In particular, there are 4 reasons to attempt at converting Protestants: (1) Living in heresy is destructive, (2) The Church must be whole and unified, (3) Christ prayed for unity, and (4) Catholics have always attempted to end heresies.
Heresy creates a tear in the garment of Christ. It is an act of evil to split from any of the teachings handed on faithfully from the apostles. St. Peter called those who taught heresy “false teachers” that “bring in destructive heresies” (2 Peter 2:1). Did those false teachers love the Lord? Most likely. Yet, St. Peter did not say, “Well, they love the Lord, so let's ignore their false teachings and only focus on the positives.” No. Any false teaching is called a “destructive heresy.” According to the Bible, heresy is destructive. To call it anything else would be an unbiblical mindset.
Unity within the Church is a necessity. St. Paul said, “I appeal to you, brothers, by the name of our Lord Jesus Christ, that all of you agree, and that there be no divisions among you, but that you be united in the same mind and the same judgment” (1 Corinthians 1:10). Why is this? Because doctrine matters. Jesus said, “I am the way, and the truth, and the life” (John 14:6). If Jesus is the truth, then if two Christians disagree over truth/doctrine, then they don’t know Jesus. Faithfully knowing and propounding the truths of Jesus Christ is of the utmost importance if one knows Jesus – the truth.
According to the prayer of Jesus, agreement in doctrine is a persuasive reason for non-Christians to join the Church. Jesus knew that the integrity of the Church's message would be ruined if there were divisions, so He prayed, “[may] they [apostles]…all be one, just as you, Father, are in me, and I in you, that they also may be in us, so that the world may believe that you have sent me. The glory that you have given me I have given to them, that they may be one even as we are one, I in them and you in me, that they may become perfectly one, so that the world may know that you sent me and loved them even as you loved me” (John 17:21-23). If this is the prayer of the Lord, then should it not be our prayer as well?
The Catholic Church has attempted to correct false doctrine. St. Paul debated his fellow believing Jews in every synagogue that he went, urging them to accept Christ as the Messiah and join the New Covenant Kingdom of God. Yet if a Catholic attempted to imitate St. Paul, he frequently would be brushed aside as "extreme" or "traditionalist." The early Christians wrote against heresies all the time (ex. St. Irenaeus's "Against Heresies" or Tertullian's "Against Marcion") and rebutted them frequently in their Scripture commentaries. Even St. Augustine in the 5th century publicly debated members of the Donatist heresy. This is a practice with deep roots in the Church, and prompted St. Alphonsus Ligouri to write out a refutation against every heresy in the history of Christianity in the 18th century. Is this traditional history of the Church suddenly to be considered outdated?
The Lord does not want there to be a separation between Catholics and Protestants. They need to be one, as the Lord is one with His Father in Heaven. To simply sweep the differences between them under the rug and act like everything is okay is an unbiblical attitude. The Church fought against Gnostics, Arians, Pelagians, Donatists, Albigensians and other heresies throughout her history. Where has the zeal gone to bring all people fully into the Kingdom of God? There needs to be, as Christ said, “one flock, [and] one shepherd” (John 10:16). Let us all work diligently for the reunion of all Christians.