What is the difference between Catholics and Protestants?

I am periodically asked, what is the difference between Catholics and Protestants? Sometimes, it is from visitors to the church looking into things. Sometimes, it is from local Muslims trying to understand the various Christians they may interact with. Other times, it is young believers who have found their way to us, wondering how and why we might be different.

There are, of course, lots of differences between Catholics and Protestants. Some of them very serious, many of them much less so. There are all sorts of differences we could point out. Fundamentally, though, I tend to land hard on just two.

Ultimate authority in matters of faith

The first key difference is our respective views in matters of faith. Who, or what, has ultimate authority regarding matters of faith and practice? Specifically, what can lay claim to ultimately relay God’s words? If there is a dispute between Christian believers, to what authority can they appeal which cannot be topped by any other?

For the Catholic, the answer to that question is The Pope. It is the office of pope – particularly as he speaks ex cathedra – that is the highest authority in the church. Should the Bible say one thing, but the pope says another, the ultimate arbiter of truthfulness is the pope. As St Ignatius of Loyola put it:

What seems to me white, I will believe black if the hierarchical Church so defines.

The doctrine of Papal Supremacy is quite clear in this regard. The Catechism of the Catholic Church states, ‘the Roman Pontiff, by reason of his office as Vicar of Christ, and as pastor of the entire Church has full, supreme, and universal power over the whole Church, a power which he can always exercise unhindered.’ Similarly, the pope enjoys ‘supreme, full, immediate, and universal power in the care of souls’.

By contrast, Protestants insist that ultimate authority in matters of faith and practice lie with scripture alone. Michael Reeves, in his book The Unquenchable Flame, writes:

[To] achieve any substantial reformation, it took Luther’s attitude, that Scripture is the only sure foundation for belief (sola Scriptura). The Bible had to be acknowledged as the supreme authority and allowed to contradict and overrule all other claims, or else it would itself be overruled and its message hijacked. In other words, a simple reverence for the Bible and acknowledgment that it has some authority would never have been enough to bring about the Reformation. Sola Scriptura was the indispensable key for change.

Protestants insist the Bible is God’s revelation of himself to us. Neither the Church – with its papal office – nor human reason could be considered a higher authority than the words of scripture itself.

One essential difference, then, between Catholics and Protestants concerns their source of ultimate authority. Is the Bible, or the Church, the highest authority in matters of faith? If there is disagreement, is it scripture or the pope who may ultimately rule?

The means of justification

Closely linked to the matter of authority is the means of justification. Is our justification before God a matter of faith alone or faith and good works? Are we made right with God simply by believing in Jesus or through a combination of belief and works?

Whilst Catholicism teaches that faith is certainly necessary for justification, that is merely the starting point. Both faith and works, according to the Catholic Church, are necessary. The Catholic Church Catechism teaches the following added requirements:

The necessity of the church: ‘Basing itself on Scripture and Tradition, the Council teaches that the Church, a pilgrim now on earth, is necessary for salvation.’

The necessity of baptism: ‘Justification has been merited for us by the Passion of Christ. It is granted us through Baptism’ and, further, ‘Baptism is necessary for salvation for those to whom the Gospel has been proclaimed and who have had the possibility of asking for this sacrament. The Church does not know of any means other than Baptism that assures entry into eternal beatitude.’

The necessity of communion: ‘The Eucharist is thus a sacrifice because it re-presents (makes present) the sacrifice of the cross, because it is its memorial and because it applies its fruit.’

‘The liturgy in which the mystery of salvation is accomplished concludes with the sending forth (missio) of the faithful, so that they may fulfill God’s will in their daily lives.’ (my emphasis added)

The Council of Trent further insists:

The necessity of good works: ‘If any one saith, that by faith alone the impious is justified; in such wise as to mean, that nothing else is required to co-operate in order to the obtaining the grace of Justification, and that it is not in any way necessary, that he be prepared and disposed by the movement of his own will; let him be anathema.’

The Catholic Church thus teaches that faith and works are necessary for justification. We are made right with God through a combination of faith and works.

Protestants, by contrast, teach that justification is by faith alone in Christ alone. Justification is the free gift of grace won by Christ and applied by the Holy Spirit. The benefits of the atonement, according to Protestants, are received by faith alone. Bruce Milne, in his systematic theology Know The Truth, states it this way:

This act whereby God remits the sins of guilty men and women, accounting them righteous on the basis of Christ’s representative obedience and redemptive death, is called in scripture justification (Lk. 18:14; Rom. 3:24; 4:25; 1 Cor. 6:11; Tit. 3:7). It is in no way a reward for our own righteous efforts nor in any respect a matter of our co-operating with God to make any moral contribution to our justification. Justification is an act of sheer unmerited mercy on God’s part.

He says elsewhere:

Justification is that work of God’s grace whereby the sinner through his faith-union with Christ is accounted righteous before God on the grounds of Christ’s obedience and death. It is crucial to recognize that justification refers to the status of righteousness which God grants the believer and not primarily to actual intrinsic righteousness. It is this fact which is the basis of the Christian’s peace, security and joy. Sinners as we are, we are accepted – not on the ground of feeble efforts to obey God adequately; but on his crediting us with the perfect righteousness of Christ.

Wayne Grudem states it this way in Bible Doctrine:

Scripture never says that we are justified because of the inherent goodness of our faith, as if our faith has merit before God. It never allows us to think that our faith in itself earns favor with God. Rather, scripture says that we are justified “by means of” our faith, understanding faith to be the instrument through which justification is given to us, but not at all an activity that earns us merit or favor with God. Rather, we are justified solely because of the merits of Christ’s work (Rom. 5:17-19)

He goes on to say:

[F]aith is the opposite of trusting in ourselves, and therefore it is the attitude perfectly fits salvation that depends not at all on our own merit but entirely on God’s free gift of grace… This is why the Reformers from Martin Luther on were so firm in their insistence that justification comes not through faith plus some merit or good work on our part but only through faith alone.

There are lots of other differences we can highlight between Catholics and Protestants. But these are the two most crucial. The Reformers looked into the scriptures and believed that it taught justification by grace alone, through faith alone, in Christ alone, to the glory of God alone. The Catholic Church, by contrast, determined that it came by faith in Christ and by good works, baptism, communion and the church itself. When faced with an evident difference of opinion, the question became who had more authority: the scriptures or the pontiff.

In the end, these are the crucial differences. Do the scriptures or the church act as ultimate authority for our faith? Is the means of justification a gift of God received by faith alone or is it something we receive by faith and good works? The answer makes all the difference in the world.