The Lord calls Christians to serve him with decaying bodies amid the discomforts of a groaning creation, the hostility of a faithless world, and the malice of Satan and his demons, until we face that shadow of our ultimate enemy, physical death. In this we need holy courage. Faith in Christ should prepare us to endure suffering and to act according to our duty undaunted by opposition, whereas those who practice cowardice (because they have not believed in him) receive their portion in the lake that burns with fire and sulfur (Rev. 21:8). Courage, then, is no optional part of the Christian life, and the Bible makes much of an outstanding example of it: the soldier’s valor—not to glorify human wars, most of which may be unjust, but to teach us the realities of spiritual warfare. Any Christianity that ignores these teachings or explains them away as dead metaphor is a distortion of the faith—another religion, really—cruelly pretending we can be carried to the skies on flowery beds of ease.

So, we are soldiers whether we like it or not. And, as soldiers, there’s something we ought to be doing, which soldiers have always done. We ought to sing soldier-songs to bolster our own and each other’s courage, as modeled by the Psalms (18:29–42; 27:3; 144:1–2). We think Isaac Watts’s “Am I a Soldier of the Cross” may be the greatest English-language hymn in the genre. The opening question is convicting. What kind of a soldier hesitates to acknowledge his commander’s cause as his own? A traitor? An undercover agent? The question awakens in us disgust at behavior we know only too well. Who among us, living and working with people who hate our commander, who ridicule his ordinances, and who persecute his vanguard, has never felt ashamed of the cross? Thus the first stanza weakens pride that could otherwise inoculate us against the message of this hymn, and the spiritually-minded singer strengthens his resolve to take a stand for the gospel.

The rhetorical irony in stanzas 2–3 further stings. In our first study (A Mighty Fortress Is Our God) we wrote, “all hymns make congregants say things, the truth of which they may or may not in the moment feel existentially.” As employed here, the device is convicting in the extreme. Watts lets us indulge in a form of speech that perhaps comes naturally to our lips; indeed, it is the coward’s favorite: the complaint or whine. But there’s nothing natural about the content of this complaint! Only a work of grace could make us mean it, for we find ourselves complaining like heroes, like a valiant soldier unhappy to find himself left behind in reserve on the eve of battle—complaining not about difficulty but about ease, not about opposition but about a lack thereof. The irony is instructive, for the sin that makes us unlikely ever to complain this way on our own is the very thing that makes us too weak for battle. By putting such words in our mouths, the hymn trains us to deplore the very comforts and worldly acceptance that, in our cowardice, we are inclined to idolize. The first half of the hymn works like a drill sergeant, provoking us to “act like men” (1 Cor. 16:13).

Which is just what we do in the second half. In stanza 4 we ask for more courage, we promise to “bear the toil, endure the pain,” and we recall God’s promises of presence and support. There are hundreds of these in his Word, but, in the spirit of the hymn’s first half, we cite one that chides:

I, I am he who comforts you;
   who are you that you are afraid of man who dies,
   of the son of man who is made like grass,
and have forgotten the Lord, your Maker,
   who stretched out the heavens
   and laid the foundations of the earth,
and you fear continually all the day
   because of the wrath of the oppressor,
when he sets himself to destroy?
   And where is the wrath of the oppressor? (Is. 51:12–13)

Then, in stanzas 5–6, we close in hope. Our current crosses and disappointments seem small compared to the glory that awaits us: His glory, the enjoyment of which is our chief end.

The poem needs a simple and absolutely unpretentious tune like MARLOW. Singable, yet distinctive, its arpeggios and repeated pitches mimic a military signal, calling us to enter the field against evil within and without, under the victorious banner of Jesus, the founder and perfecter of our faith.