The gift of grace is truly a freely bestowed treasure given by God. It is not something that we can earn, merit, or purchase. There are no hoops to jump through or qualifying steps to take in order to receive it. God gives it to those whom He chooses for the purpose of His own glory. As to our response to His work of grace, the sinner who is dead in his sin receives the work of God's grace whereby He is quickened to faith. The immediate consequence of the moving of God's Spirit in his heart is an overwhelming awareness of sin and the desire to be forgiven for sin's affront to a holy God.
Consequently, repentance and the calling out to Christ Jesus for the forgiveness of sin is the initial indications of what God has done by grace in their lives. This is also described as "receiving Christ" as personal Savior. John 1:12 states clearly that: "But as many as received Him, to them He gave the right to become children of God, even to those who believe in His name." Thus, with a heart filled with faith, we receive the gift of God's grace by faith in the Son of God.
I trust this helps. Feel free to follow up with additional questions.