Doing something to or for the glory of God does not add anything to God, because God’s glory isn’t something like a bank account, not something that can be increased or diminished. It is not a possession at all, in the sense that a person might possess a house. God could not set aside or dispose of His glory, any more that a beautiful painting could set aside its beauty.
But if to do something for God’s glory is not to add anything to God, then what is it?
When we are encouraged to act for the glory of God, it is we who are the object of concern, not God, the variable in the equation is the state of our own mindful spirit.
When a child does something admirable, her mother’s love and concern and effort in raising the child are validated, are brought to their intended and longed-for realization. It does not add anything to the mother, it is the fair fruition of her parentage, and so to her glory.
The acorn is the glory of the oak.