People from all over the world join the American Military, so there is an endless, and very confronting clash of world views.
However there is one concept that is prevailing within the military, (as far as I've seen) and that is the idea that "nothing is given, everything is earned". As a matter of fact, I overheard this being said even today. As I watched that gentleman walk away, I thought to myself, "how on earth could I witness to someone who thinks like that everything he will ever have must be earned?
Grace It is the very nature of the grace of God, that it cannot be earned. And if we imagine we can do something to merit salvation, we've not just diminished the work of God in part, but in totality, we have separated salvation from grace altogether. The idea that a deed can be good enough to merit salvation means that it is so devoid of sin, so perfect, so priceless, and so transcendent that it has granted a person the very right to be in the presence of God, and abide with Him forever. This idea is completely unsupported and foreign by scripture. We can actually do nothing that is perfect, nothing that could in anyway be near perfect enough to earn what God offers. It is true, however, that in this world just about everything must be earned. Honor, respect, rank, prestige, etc. but this is just another way the the Christian world view is a complete contradiction to the world we live in. Grace is free. Grace is given to us despite our sin, and without us striving for it.
What we must not do The problem lies in our inability to understand how grace could possibly be free. “How is it”, they ask, “that if I am so sinful that I could be given salvation without having to do anything deserving of it?”. And this is is precisely where we must make a crucial differentiation. We are not to promote some philosophical thought or logical scheme, (although those have their proper place as maid servants of theology) but we are to proclaim the gospel of our Lord Jesus Christ.
“Christ, by His obedience and death, did fully discharge the debt of all those that are thus justified, and did make a proper, real and full satisfaction to His Father's justice in their behalf. Yet, inasmuch as He was given by the Father for them; and His obedience and satisfaction accepted in their stead, and both, freely, not for anything in them; their justification is only of free grace; that both the exact justice, and rich grace of God might be glorified in the justification of sinners.” -Westminster Confession ch. 11
What we must remember The one who is proclaiming the word of God actually has no power. This would seem to undermine the original question, and it should. To assume that by some virtue we have of our own is how people are saved, is ridiculous. The salvation of God is precisely that, of God! It is by His word and Spirit that people are saved. This is a glorious burden lifting truth. The immense weight that some bare because of the burden they place on themselves to say just the right thing, or know every kind of apologetics etc. is exhausting. Don’t get me wrong, those things are great to study and learn, but first we must know and trust that the word of God will do exactly what God intends it to do. We don’t need to worry that we haven’t read all of The Institutes, or Turretin’s theology, or studied in depth the vast apologetic work that Ravi or James White. The word of God will accomplish His will, we must only be faithful.