But because of the Cross, you have full access to God's grace. Grace is God's kindness and graciousness toward you without regard to worth or merit. You can't earn grace, you can't buy grace, and you can't barter with God to receive grace. It is a free gift of God to you. There is only one thing you can do related to grace, and that is to receive grace.
Many people have that tendency, especially if they grew up with an inferiority complex . . .
The reality is, you can never do enough. There is no end. You can never do enough to thank God for sending Jesus to the cross. You can never do enough good works to equal what Jesus Christ did in dying for your sins. You can never do enough to compensate Jesus for His sacrifice on your behalf.