Godfrey Cass, the elder son of Squire Cass, is looked upon by the people of Raveloe as a decent, serious, and potentially prosperous young man who may even have made a match with the town's sweetheart, Nancy Lammeter. In fact, he is described quite positively at the beginning of chapter 3, especially when contrasted against his brother, Dunstan. However, the narrator explains that things with Godfrey are changing, all caused by Dunstan's negative influence.
..it would be a thousand pities if Mr. Godfrey, the eldest, a fine, open-faced good-natured young man, who was to come into the land some day, should take to going along the same road with his brother, as he had seemed to do of late.
Dunstan and Godfrey have a master/servant relationship. Dunstan, who is described as
a spiteful, jeering fellow, who seemed to enjoy his drink the more when other people went dry
has obviously persuaded Godfrey into following his irresponsible and carefree ways to the point that Godfrey has fallen prey to many of Dunstan's tricks, always ending up in the losing end. Although Dunstan is described as "dull" in mentality, he does find ways to have things go his way when there is something good for him in the end. In this fashion, he has manipulated Godfrey into drinking, borrowing money, and entering in shady deals. This is not known to the general public but, from what the dynamics between the brothers suggest, Godfrey is slowly allowing Dunstan to control him.
One of these instances occurs in chapter 3 when Godfrey demands that Dunstan pays back money that he owes, to which Dunstan responds that he will not, and that he will make Godfrey do it. In an act of what at first looks like courage, Godfrey threatens to punch his brother, only to be laughed at by Dunstan. Moreover, Dunstan threatens Godfrey by telling him that he will divulge his secret: that Godfrey married a low-life woman, an opium fiend at that, and that they had a child together.
Powerless, Godfrey has to hold back. Yet, the language used by Eliot shows Godfrey a man who is actually much weaker than character than what meets the eye; one whose brother has dominated and somewhat emasculated him
[Godfrey's] natural irresolution and moral cowardice were exaggerated by a position in which dreaded consequences seemed to press equally on all sides, and his irritation had no sooner provoked him to defy Dunstan and anticipate all possible betrayals than the miseries he must bring on himself by such a step seemed more unendurable to him than the present evil.
In other words, Godfrey was no different than his brother in terms of immorality; he had indeed married the low-life woman, he was in debt, he was drinking more and more in the company of Dunstan, and he was too weak of character to face up to his mistakes. Eliot does not feel sympathy for Godfrey, and the language is contemptuous. Yet, this is all part of what later would become Godfrey's redemption, as well as the end of the sorrows that he suffers at present.