For the grace of God has appeared that offers salvation to all people.
Titus 2:11 (NIV)
We all used to say that God's grace is undeserved favor. Which means that not only does this favor ask us nothing in return, but that we can do nothing to deserve it. Besides, that is why it is a grace. There is also another more explicit way of defining grace: “It is the sovereign act by which God justifies sinners who deserve his righteous wrath."
By defining grace as an act of God, we can understand that it is an active and dynamic law working for the forgiveness and salvation of sinners. However, even if it is active, it has effect only in the lives of those who receive it by faith, as we read in Ephesians 2:8, "For by grace you are saved through faith."
For some, the grace of God is a one-time event that happened in the life of new believers at the time of their conversion, which is totally false. The Christian faith is founded and strengthened by the grace of God. We live by grace. The only way to fully receive God's grace is to recognize our need for God and believe in His Son through whom that grace was made possible at the cross.