The Son here is your own imagination, the exact image of the Father, which is awareness of being, the I AM in you. He is called the brightness of that glory because imagining is the shining-out of pure awareness into form, and he upholds all things by the word of his power because whatever you assume and speak inwardly as true sustains the world you then see. Nothing stands except by that inner word.
A sin, in this reading, is a missing of the mark, an assumption you no longer wish to keep. Imagination purges it by itself, without help, simply by assuming the wished-for state instead. Then it "sits down at the right hand," meaning the creative power rests in the position of authority within you. Your own imagining is the maker and sustainer of your circumstances.