Just as the Apostle Paul speaks of a distinction between "godly sorrow" and "sorrow of the world" (2 Cor. 7:10), so a distinction can be made between Christian humility and secular or worldly humility. The latter is often portrayed as a virtue that characterizes the good man considered in himself; the former acknowledges the good gifts in a believer in a manner which exalts the grace of God, as Paul does in 1 Cor. 15:10, when he says "...but I laboured more abundantly than they all: yet not I, but the grace of God which was with me."
Charles Hodge in his Exposition of the First Epistle to the Corinthians, p. 318, helps to flesh out the reality of our cooperation with the grace of God and how that squares with the principles that all good in us is to be ascribed wholly to the grace of God: "Yet not I, i.e. the fact that I laboured so abundantly is not to be referred to me; I was not the labourer — but the grace which was with me....In the one case grace is represented as co-operating with the apostle; in the other, the apostle loses sight of himself entirely, and ascribes every thing to grace. 'It was not I, but the grace of God.' Theologically, there is no difference in these different modes of statement.... True, he did co-operate with the grace of God, but this co-operation was due to grace — so that with the strictest propriety he could say, 'Not I, but the grace of God.'"
Hodge further gives us a definition (p. 317) that is worthy to meditate upon: "Christian humility does not consist in denying what there is of good in us; but in an abiding sense of ill-desert, and in the consciousness that what we have of good is due to the grace of God."