“Ask a Priest: How Does a Priest Know What He Believes Is True?”

Q: How do you know that what you believe is right? The devil confuses people and tells them all kind of lies. So as a priest, how do you know that what you believe is correct and not just another lie? I mean no disrespect. -D.W.

Answered by Fr. Edward McIlmail, LC

A: Thanks for your note. Yours is one of the great questions that everyone has to grapple with in his own life. How can we be sure of what we believe? Scripture warns us, “Do not trust every spirit but test the spirits to see whether they belong to God” (1 John 4:1).

So how do I know that what I believe is correct? The short answer is: I see what the Church says.

God is truth. He “can neither deceive nor be deceived” (Catechism, No. 156). In other words, God won’t contradict himself. So he won’t reveal one thing to the Church and then reveal to me something that contradicts what he revealed to the Church. That would be confusion — a telltale sign of the devil’s presence.

What my reliance on the Church means in practice is this: When I tentatively embrace a belief or opinion, I can try to check its validity by looking at what the Church says on the topic. If my tentative view matches what the Church says, or at least doesn’t contradict what the Church teaches, then I can be reasonably sure that I’m heading in the right direction.

But this, in turn, raises an obvious question. How do I know what the Church teaches is true?

Here I could research and discover that Church teaching does not contradict Scripture. I could also look at Church documents over the centuries to see if there is continuity in the teaching. Church documents have lots of footnotes referring to earlier ecclesial documents. Ultimately, though, I trust the Church because I trust Christ; he founded it, and the Holy Spirit guides it.

This doesn’t mean, however, that the Church has an easy answer for everything. Life isn’t that simple. In fact, the Church admits its limitations. Vatican II’s pastoral constitution, Gaudium et Spes, says, “The Church guards the heritage of God’s word and draws from it moral and religious principles without always having at hand the solution to particular problems” (No. 33).

That was written in 1965. The world has gotten a lot more complicated since then. So grappling with modern-day problems takes prudence, prayer, and research.

A practical criterion that helps is this: Whatever is true is reasonable. Faith and reason go together; God invented both, so they won’t contradict each other. Some points of the faith go beyond what reason can discover (such as the Trinity), but they are not unreasonable. That is a fine distinction.

The truth is like a path through a forest. It takes two feet to walk the path – in this case, the foot of faith and the foot of reason. By alternating between faith and reason, we find that we can go deeper into the forest and experience it better.

I could go on, but perhaps this reply would answer your question in a sufficient way. Feel free to send further questions if you have them. (For more reading on God’s revelation of truth, and how the Church discerns it, see the Vatican II dogmatic constitution Dei Verbum). I hope this helps.