The distinction and relation between the internal and the external worship of God, discussed often in this space, is of utmost significance. Below is Niels Hemmingsen’s discussion of what each is and of how they are to cohere in the same acting subject. Especially important is his reminder that “spiritual” does not mean (only) “internal” or “invisible.” 1 Rather, anything done from faith in accordance with the law and will of God is properly spiritual. 2 The criterion of spiritual action is not whether we can see it: the criterion is whether whatever is done, internally or externally, is done in accordance with the truth.
Thus the actions commanded in the second table of the Decalogue are themselves spiritual acts of worship: which is to say, the physical love of neighbor, arising from faith, is spiritual worship of God. The problem with whitewashed tombs is not that they look fine on the outside. The problem is that they are tombs.
In universum itaque cultus Dei duplex est, Internus et Externus. Utrumque Deus iure a nobis requirit. Nam quoad animam creavit Deus hominem ad imaginem et similitudinem suam, quoad corpus, omnes vires contulit et conservat. Nec pugnat haec distinctio cum eo, quod supra dictum est, omnem cultum Dei spiritualem esse debere. Est enim cultus Dei ex causa efficiente, Obiecto et finali causa censendus. Cum igitur omnis cultus Dei proficisci debeat ex fide, quam spiritus operatur in gloriam Dei, qui spiritus est, recte spiritualis omnis cultus Dei verus iudicabitur.
Sed quid est Internus Dei cultus? Est motus mentis et cordis congruens cum lege Dei.
Quid Externus? Cum actio externa congruit cum lege et voluntate Dei.
Sed uterque iuxta duplicem Decalogi tabulam dividendus est. Nam ut prima tabula praecipit cultum Dei internum et externum, ita et secunda. Primae tabulae cultus internus et externus habet gradus supra in explicatione Decalogi commemoratos. Ex hoc cultu primae tabulae manat duplex cultus, internus et externus secundae tabulae: Internus consistit in affectu cordis erga proximum: Externus in operis declaratione. Paulus 1. Thess. capite 1. dividit cultum Dei compendiosius adhuc, nimirum in affectus tres, et eorum effectus totidem. Affectus sunt: fides, spes et caritas: Fidei tribuit ἐργὸν, Spei ὑπομονὴ, Caritati κόπον.
Considered as a whole, then, the worship of God is twofold, internal and external. God rightly requires each of us. For with respect to the soul, God created man according to his image and likeness; with respect to the body, he has bestowed and preserves all its powers. Nor does this distinction conflict with that which was given above–[namely,] that all worship of God ought to be spiritual. For the worship of God ought to be assessed with a view to its efficient cause, its object, and its final cause. Since, therefore, all worship of God ought to proceed from faith, which the Spirit works to the glory of God, who is spirit, all true worship of God will rightly be judged to be spiritual.
But what is the internal worship of God? It is a motion of the mind and heart harmonious with the law of God.
What is the external [worship of God]? When external action is harmonious with the law and will of God.
But each [of these] should be divided according to the two tables of the Decalogue. For, as the first table commands the internal and external worship of God, so also [does] the second. The internal and external worship of the first table has the degrees mentioned above in the explication of the Decalogue. From this worship of the first table flows the twofold worship, internal and external, of the second table: the internal worship [of God] 3 consists in the affection of the heart toward one’s neighbor; the external [consists] in one’s making evident [his internal affection] through work [in operis declaratione]. Paul in 1 Thessalonians 1 still more briefly divides the worship of God–namely, into three affections and their corresponding number of effects. The affections are: faith, hope, and charity. Faith yields work, hope [yields] endurance, charity [yields] toil. 4 (Enchiridion Theologicum, pp. 176-7)