Grace is unmerited favor. Oswald Chambers adds that, "The gospel of the grace of God awakens an intense longing in human souls and an equally intense resentment, because the truth that it reveals is not palatable or easy to swallow. There is a certain pride in people that causes them to give and give, but to come and accept a gift is another thing. I will give my life to martyrdom; I will dedicate my life to service I will do anything. But do not humiliate me to the level of the most hell-deserving sinner and tell me that all I have to do is accept the gift of salvation through Jesus Christ." 
The grace and mercy of God strikes at the very heart of humanity. It has the ability to raise the most extreme emotions by, as Oswald Chambers says, humiliating those who want to add something to their salvation. On the other hand, it can spark emotions of humility where one will "consider everything a loss compared to the surpassing greatness of knowing Christ Jesus my Lord, for whose sake [we] have lost all things" and counting them as "rubbish" (Phil. 3:8). This very grace came/comes through Jesus (John 1:17; Romans 5:15; 1 Corinthians 1:4; 2 Timothy 1:9), a sufficient grace (2 Corinthians 12:9) that is shown through the "redemption through his blood" and "forgiveness of sins" (Ephesians 1:7) and it is this grace by which we are justified (Titus 3:7) and saved (Ephesians 2:8).
Peter tells us to "set your hope fully on the grace to be given you when Jesus Christ is revealed" (1 Peter 1:13), for we worship the "God of all grace" (1 Peter 5:10). Lastly, because we are saved through the work and grace of Jesus, we may approach "the throne of grace with confidence, so that we may receive mercy and find grace to help us in our time of need" (Hebrews 4:16).