Updated, for today's readers, the following is from Edwards' sermon "Grace Never Overthrown." It is part of the series Charity and Its Fruits, Edwards' well-known exposition of 1 Corinthians 13. His original sermon can be read at The Jonathan Edwards Center at Yale University.
False grace is a superficial thing. It is an external show of shallow emotions and affections, but it doesn’t change a person’s nature. True grace reaches to the bottom of the heart and creates a new nature. No wonder true grace is much more abiding than false grace.
If there’s nothing in the heart but counterfeit grace, corruption will not be mortified. False grace may seem to strike a wound against sinful corruption, but if so, it’s only slight and little. It will not reach the heart of corruption or diminish the strength of the principle of corruption. Sin will remain in the soul in its full power. We shouldn’t be surprised when corruption ultimately prevails over false grace.
True grace is much different. It goes to the heart of sin, lashing and wounding until the sin is finally mortified. Upon first entering a soul, true grace strikes a mortal blow against sin and continues in constant conflict with it. We shouldn’t be surprised, then, that true grace keeps possession of the soul and ultimately prevails over its enemy.
Counterfeit grace can never remove sin’s dominion over the soul, which is why it doesn’t last. By nature, true grace is contrary to the reigning power of sin. As soon as it enters, it takes possession of the heart away from sin. It takes over the throne. Thus, it keeps its seat in the soul and finally prevails against the enemy.
Counterfeit grace might affect the heart somewhat, but it isn’t rooted in any real conviction of the soul. True grace begins with real and thorough conviction, so it tends to persevere on a solid foundation. True grace has something of the divine nature, which is a powerful, supernatural, and heavenly. You can see this in how true grace causes desires for perseverance. The one who has it is hungry and thirsty for perseverance, and more aware of the dangers that surround them. True grace makes people sensible, awakens them, and excites them to higher levels of watchfulness and spiritual concern. Those who have it strive diligently to persevere, looking to God for help, trusting him for protection from the many enemies who stand in opposition.