Show me one reference from scripture that grace comes through the organized church rather than from God.
There is ample evidence in the NT that there was an organized church. The community of believers met together daily, devoting themselves to prayer, breaking of the bread, the teaching of the Apostles and fellowship.
Deacons were appointed to distribute the contributions of the faithful to the widows, the orphans and the poor.
In Galatians, St. Paul instructs them to have ready for him the collection taken on Sundays, donations which the believers have “set aside” for this reason.
The very fact that there was a council in Jerusalem, and letters to the church in different cities shows a conscience and concerted effort to maintain unity of belief and doctrine.
The fact that men were chosen to insure that the teachings would be unified and passed on after the deaths of the Apostles shows organization and thought for the future.
That is the Church and that is the means by which we learn of God’s grace or receive His grace.
All grace is from God, the grace of mercy which is His alone to give, and the grace of divine assistance which Jesus gives us by the Holy Spirit through the church.