We have noted before Thomas's admiration for Andrew Fuller. He quotes Fuller at the end of a sermon on John 3:16 preached in Abersychan on 21 November 1827 in the afternoon and calls him "that extraordinary and illustrious character". Fuller says “Your eternal all depends upon it: for believing in Christ you are saved; but not believing in him there is no escaping.”
In a note found in one of the volumes of sermons on the book of life he quotes Fuller again and calls him a great writer. Fuller says (in his commentary on Revelation) "The blessed God is represented as keeping a register of his servants, not as elect, or as redeemed, or as called, but as his professed followers. When any turn back, their names are blotted out. Hence at the last judgment it is made the rule of condemnation.