For if our preaching were a matter of display and ambition, it would have been right to jump from one subject to another and change about continually, taking no thought for you, but only for your applauses. But since we have not devoted our zeal to this, but our labors are all for your profit, we shall not cease discoursing to you on the same subjects, till you succeed in learning them. For I might have said much about Gentile superstition, and about the Manichæans, and about the Marcionists, and by the grace of God have given them heavy blows, but this sort of discourse is out of season. For to those who do not yet know accurately their own affairs, to those who have not yet learned that to be covetous is evil, who would utter such discourses as those, and lead them on to other subjects before the time?