Why We're Not Roman Catholic #9 - The God Rome Can No Longer Define: Why Christians and Muslims Don’t Worship the Same God

Some people—both Roman Catholics and Protestants—will agree that a Reformation was necessary back then because of corruption in the church. But many also believe that we’ve moved past those issues, and that division is no longer warranted. The problem with this reasoning is that it assumes Rome has improved. In truth, its errors have only grown worse. As we’ve seen throughout this series, Rome’s doctrines have become even more solidified and anti-biblical—especially regarding the Gospel, the pope and Marian dogmas. And perhaps most tragically, this also includes their understanding of God Himself.

There was a time when the Roman Catholic Church boldly defended the exclusive truth of the Christian God as revealed in Scripture—the Triune God: Father, Son, and Holy Spirit. But in recent decades, Rome has adopted an ecumenical posture that undermines this clarity, especially in relation to Islam. In its attempts to find common ground, the Roman Church has confused categories, softened essential truths, and ultimately surrendered one of the core confessions of the Christian faith: the identity of the one true God.

The turning point came at Vatican II, particularly in the document Lumen Gentium, which states: “The plan of salvation also includes those who acknowledge the Creator, in the first place amongst whom are the Muslims; these profess to hold the faith of Abraham, and together with us they adore the one, merciful God...”

This was not revolutionary because of its generosity, but because of its theological ambiguity. It suggested—or at least implied—that Christians and Muslims “together” adore the same God. This idea has only been reinforced since. In 2019, Pope Francis and the Grand Imam of Al-Azhar signed the Document on Human Fraternity, which included this stunning statement: “The pluralism and the diversity of religions... are willed by God in His wisdom.” Statements like these muddy the theological waters and send the message that doctrinal truth can be relativized in the name of social harmony. But this is not merely an ecumenical problem—it is a theological crisis.

True Christians must be clear: we do not worship the same God as Muslims. The Quran explicitly rejects the Trinity, calling it blasphemy to associate anyone with Allah. Surah 4:171 and Surah 5:116 deny the Sonship of Christ and the idea that God could ever have a Son. Islam confesses a strictly unitarian deity: Allah is one in a solitary sense, and Jesus is merely a prophet, not God incarnate. On top of that, the character and attributes of Allah are not the same as those of the God of the Bible. To claim that the god of Islam is the Triune God we worship is not a small theological inaccuracy—it leads people into false worship and idolatry. And this reasoning applies to all religions that reject the Son, whether Hinduism, Buddhism, modern Judaism, or Christian cults like Mormonism and the Jehovah’s Witnesses.

Christians confess that the only true God is Father, Son, and Holy Spirit, and that no one knows the Father except through the Son (Matt. 11:27). The apostle John warns: “Whoever does not honour the Son does not honour the Father who sent him.” (John 5:23) and “No one who denies the Son has the Father.” (1 John 2:23). So whatever moral or monotheistic similarities we might share, the truth remains: a god who is not the Father of our Lord Jesus Christ is not the true God.

Now, I understand the appeal of Rome’s movement here. In a post-truth culture, vagueness is considered a virtue. The idea is that by being vague, we can hold our own beliefs while coexisting more peacefully with those who believe differently. But theological vagueness is not bridge-building; it’s gospel-denial. It’s the illusion that we can all meet halfway and live on the bridge itself. Many evangelicals are guilty of the same compromise—not always with Muslims, but with others, accepting false teaching and heresy in the name of peace.

We must be convinced that true peace and true unity come from truth. We should seek meaningful and cordial dialogue with Muslims—but that begins with a clear understanding of our differences. The moment we say, “It’s all the same, just different details,” we shut the door to the very gospel we’re called to proclaim.

Rome’s attempt to forge theological unity through diplomacy has cost it the ability to define the God it claims to worship. Its catholicity is no longer biblical; it’s institutional. And by compromising on the very nature of God, Rome has ceased to guard the faith once for all delivered to the saints.

The true Church—those who worship in spirit and in truth—must lovingly but firmly reject this error and proclaim the only true God: Father, Son, and Holy Spirit—not a generic deity of interfaith consensus.

“This is eternal life, that they know You, the only true God, and Jesus Christ whom You have sent.” – John 17:3

Nino Marques