God giving to us what we don't deserve.
"For it is by grace you are saved, through faith, yet not of yourselves, it is the gift of God so that no one can boast."
Water Baptism is cause for boasting. It is an action on your part, not grace, which is a gift of God to you.
God's grace in salvation is given once. The priest does not need a continual sacrifice where you go get the batteries recharged to make it effectual. Once and for all time.
Grace...God giving you what you don't deserve.
That's not what Grace is and therein lies your problem. John 1 :14 says that Jesus was full of Grace. Jesus was full of what you don't deserve?
Eph 2: 28 says we are saved by grace...........it is the gift OF God.....not FROM God but OF God. That's what Grace is. It is God Himself that is infused into our soul that MAKES us righteous. ( Romans 5:19) We are not "declared' righteous. That would be fake righteousness, something God would never do.
Peter is referring to Grace when he say we can partake of the "divine nature"1 Peter 1:4
Paul is referring to Grace when he says, "For the love of God has been poured into our hearts." Romans 5:5
Simply put Grace is the power of God that causes our will to be conformed to His will so that we have the desire and the ability to obey His commandments, to pursue holiness without which no one will see God. That is how we are saved. This gift of God is not of ourselves and therefore we cannot boast. It is not given because we have done something without God's assistance, it is given because God is merciful and wants everyone to be saved. It is an unmerited Gift of Himself. We were created for good works in Christ Jesus and God's grace is what produces good works which is God working in us.
By this infusion of God we are born again, made a new creation. This Grace is called Sanctifying Grace and it is first received in water baptism which is why Peter says, Baptism now saves you. That is why Jesus can say those who believe and are baptized will be saved.
There is another Grace and that is the movement of the Holy Spirit which causes us to seek God and to come to faith but we are not justified until we receive God's divine nature in water baptism which is why Paul says, "but you were washed, you were sanctified, you were justified in the name of the Lord Jesus Christ and in the Spirit of our God." 1 Cor. 6:11
We can fall from Grace, His divine nature, and be cut off from Christ as Paul says in Galatians 5: 4
This is why Scripture warns born again, saved believers that if they commit certain sins they will not inherit the Kingdom of God.