St. Augustine is referencing the soul and the choices that condemn humanity to the realm of sinners that must repent from having fulfilled sexual desires out of wedlock. Corruption is that of the soul, corruption of the soul from having committed immoral misdeeds that are considered sins. Corruption meant by St. Augustine is very much a sexual corruption, intended to infer a promiscuity of sexual corruption. Lust is the cardinal sin that is of essence here, to which St. Augustine hints at breaking and the internal battle within himself to fight against the internal desire to fall into his lustful ways and sin all of the time.
Corruption becomes a description for sexual eroticism and the pursuits of sexual desires. The relationships formed during the sexual liaisons become a delight of pleasure for his corruptive soul as there is no need to maintain formal lasting relationships. His delight in sinning is to create highly personal short term physical relationships that involve strictly sexual intercourse. The lustful nature of his activities is a portrayal of the biology that drives humans to procreate. Such is a biology St. Augustine refers to as corruption that is a strict perusal of sexual desires and sexual fulfillment.
St. Augustine chooses to utilize corruption to in a sense to commit social crimes of an immoral nature. The utilization corruption in soul gratification is described as an activity in self-gratification and essentially of nothing else. Satisfying such gratification is the soul’s purpose given the ambition sought by St. Augustine and therefore to utilize crime as a means to satisfy an appetite that had no other means of gratification. The collective nature of the sinful nature of St. Augustine to include petty stealing and lust which likely includes coveting of wives is viewed as a shameful necessity that has ousted man to fall victim to his lust and greed.
The profit is in the crime itself. There is not any other form of profit as the pleasure was not in the activity itself but the act of committing the activity. The rush of acting out of societal norms is the profit of one’s actions as is described by the testament of St. Augustine. Crime is utilized as the form of profit sought to gratify personal desires. The nature of the crime essentially was immaterial.