There is more than one understanding of the word grace.
8. (Christianity / Ecclesiastical Terms) Christianity
a. the free and unmerited favour of God shown towards man
b. the divine assistance and power given to man in spiritual rebirth and sanctification
c. the condition of being favoured or sanctified by God
d. an unmerited gift, favour, etc., granted by God
So that the Grace of God is mercy. And the grace one receives through communion with the church and the sacraments is divine assistance and sanctification.
Two different things.
Show me one reference from scripture that grace comes through the organized church rather than from God.