One time in a Facebook theological group that I was involved with, a Protestant stated that “Jesus nowhere explicitly commanded us to use ashes” and “There’s no Lent in the Bible, either”.

This person wanted to quibble about Lent: where every major component is discussed repeatedly in Scripture, as I have demonstrated many times: with many scores of Bible passages brought to bear.

Yet a curious double standard seems to be in play here, whether intended or not. The New Testament never mentions a host of things that Protestants of various stripes believe in. For example, it knows nothing of an “altar call” or the typical “sinner’s prayer” of evangelicals. It doesn’t mention church buildings; never uses the word “Trinity” or the frequently mentioned evangelical terminology of “personal relationship with Jesus.”

It never lists its own books. The biblical canon comes from the authority and proclamations of the Catholic Church and tradition. It doesn't teach sola Scriptura, or the concept that the Bible is the only infallible source of authority (over against Church and sacred tradition).

I've written two entire books specifically about that issue alone. It's absolutely absent from Holy Scripture, and often contradicted. Yet – oddly enough – this is one of the very “pillars” of the Protestant worldview.

Other beliefs or practices not explicitly mentioned in the Bible are Bible studies, separating young people during church services, grape juice as an element to be consecrated for communion (rather than wine), “asking Jesus into one’s heart,” a “body of believers,” Scripture interpreting Scripture (the more clear helping to understand the less clear), agreeing on “essential” or “primary” doctrines and permitted relativism regarding “non-essential” or “secondary” doctrines, denominations (vs. the biblical “one Church”).

Of course, this very idea that one must find explicit biblical proof for every doctrine or it can’t / mustn’t be believed (even with high selectivity or rank inconsistency) is not found in the Bible anywhere, either. It’s (irony of all ironies!) a mere tradition of men.

Some popular Protestant (and also often Catholic) words or phrases that do not appear in the Bible are rapture, invisible church, incarnation, virgin birth, holy communion, Lord’s prayer, Bible, original sin, fall of man, theology, go[ing] to church, grace alone, [total] depravity, unconditional election, limited atonement, irresistible grace, perseverance of the saints, spirituality, Scripture alone, pray for guidance, pray for direction, spiritual warfare, and sin nature. Faith alone only appears once:

James 2:24 (RSV) You see that a man is justified by works and not by faith alone.

Protestants manage to believe all these things (or use these words) with no problem whatever. Why? Or, more specifically, why do they believe these things, which are absent from or non-explicit in the Bible, while giving Catholics misery for similar things, or else doctrines and practices with far more indication of various sorts than the things above, that Protestants accept?

Or is it just that the Protestants who sling these sorts of “arguments” about, never think about them very deeply, or have never met a Catholic who can show that they are very weak arguments indeed?

The Catholic view on these matters is totally consistent and sensible. Here is how I expressed it in the Introduction of my first book, A Biblical Defense of Catholicism (2003):

Catholics need only to show the harmony of a doctrine with holy Scripture. It is not our view that every tenet of the Christian Faith must appear whole, explicit, and often in the pages of the Bible. We also acknowledge sacred Tradition, the authority of the Church, and the development of understanding of essentially unchanging Christian truths, as is to be expected with a living organism (the Body of Christ) guided by the Holy Spirit. A belief implicitly biblical is not necessarily antibiblical or unbiblical. But we maintain that the Protestant principle of sola Scriptura (“Scripture alone”), on the other hand, is incoherent and – I dare say – quite unbiblical.

In fact, many doctrines accepted by Protestants are either not found in the Bible at all (for example, sola Scriptura and the Canon of Scripture), are based on only a very few direct passages (for example, the Virgin Birth), or are indirectly deduced from many implicit passages (for example, the Trinity, the two natures of Jesus, and many attributes of God, such as His omnipresence and omniscience).

Let me be clear about the exact nature of my argument. I distinguished above between some things that are not in the Bible at all, in word or concept, and particular words that aren’t in the Bible, whereas the concepts certainly are.

So, for example, “Trinity” is obviously a biblical concept. I have defended it from the Bible for over thirty years (it was one of my first major apologetics efforts). But if the argument is that “since the word isn’t there [like “Lent”], then neither is the concept,” I reject that, because it doesn’t follow.

Whether a thing is “biblical” or not is referring to whether the concept or teaching is in the Bible; not necessarily a particular word to describe it.

In conclusion, as a concrete example of this difference with our esteemed Protestant brethren, someone asked on another Facebook group, why Catholics identified themselves by that title. I replied:

Why does everything have to be explicitly mentioned in the Bible for you to accept it? I vigorously dispute your premise. You ask a question based on an arbitrary tradition that you have pulled out of a hat, that isn't in the Bible itself. Why should anyone pay it the slightest attention?

Christians have as much justification to call themselves Catholics as they do to refer to the Godhead as The Holy Trinity. Neither is a biblical term, but both notions are clearly taught in the Bible. The fact that there was one Church meant that it was necessarily universal.

We say we are “Catholics” because it refers to the one true, universal Church as opposed to the unbiblical notion of denominations.