What makes Christianity unique, amongst all the other religions that are in the world?
If we understand that it is a gift, that we can contribute nothing to that gift, then we come to the conclusion: "what then becomes of our boasting? It is excluded" (Rom 3:27).
Every other faith teaches our cooperation, in some way, with God for our salvation, whether the pillars of Islam or the scales of karma.
The Christian faith teaches the absolute dependance of people on God for all aspects of salvation. Therefore a Christian cannot feel that he is better than his unbelieving friend, relative or neighbor, because any righteousness, or goodness in a Christian is "God's righteousness" (3:21) working within, "for it is God who works in you, both to will and to work for his good pleasure" (Phil 2:13).
Christians then out to be the most humble people alive. But then, who would want to be a Christian? No one likes t be humbled.
But there is one more reality, "God resists the proud, but gives grace to the humble" (James 4:6). That Grace grants sonship (John 1:12), and the inheritance of heaven (Gal 3:29). The humble shall truly "inherit the earth" (Matt 5:5).
Not only that, but at the present we have the power of God to aid us a mere prayer away. We know the truth, have certainty about the future, and absolute invincibility to any deadly assault or illness, until God decides its time for us to come home.
And not only that, but we are experiencing the absolute joy, the gratification and satisfaction of being in our glory, that is in THE glory, the presence of God, in whose presence "there is fullness of joy" and at his right hand "pleasures forevermore" (Psalm 16:11).
The cost... giving up our pride, confessing our poverty and lostness, and accepting by faith that Christ died for our sins, as the Scripture says, that he was raised for our justification (that we would be right with God), as the Scripture says.
And in humility recognize that our ability to realize the truth of the gospel is a gift of God, and so we have absolutely nothing in which to take pride, save that we know him.