Grace may be the most important word in the Christian Faith. We’re saved by grace (Ep 2:8), and we stand in grace. (Ro 5:2) If we get this foundational concept wrong, we may call our theology Christian, but it will be foreign to God, and leave us with false hope.
God exhorts us to earnestly contend for the authentic, apostolic faith (Jud 3) because false teachers promote a counterfeit Christianity by changing the definition of grace, turning it into permission to indulge, essentially denying God’s nature. (vs 4)
Grace is commonly defined to be the unmerited favor of God, the idea that we may freely enjoy the blessings of God without deserving them. Since those who receive Christ are forgiven and loved by God unconditionally, the claim is that we’re free to sin against God on purpose, that even if we sin deliberately, God will never be angry or disappointed in us: He’s taken care of our sin in Christ. In other words, defining grace this way means we can receive all the benefits of salvation merely by receiving Christ as Savior, and that receiving Him as Lord is optional.
This teaching on grace effectively turns it into a type of open-ended leniency, permission to pursue our own interests, passions, and lusts. This is what Jude calls turning the grace of our God into lasciviousness, exposing those who promote this as ungodly, denying the Lordship of Christ. (Jud 4)
Routinely overlooking the willful, wrongful behavior of those we love is unhealthy at best. Claiming God is this way, and that we should be too, is foolish. God simply isn’t like this; He cares very deeply how we act, being grieved and angered by all intentional sin (He 10:26-27) This is clear in the Word, proof of His love. (Re 3:19)
The problem with the common definition of grace is that it fails to account for the miracle of the new birth, and the transforming dynamic inherent in grace. Grace isn’t freedom to sin, it’s freedom from sin (Ro 6:14); grace is God providing us a new nature (2Co 5:17) that’s inclined to obey Him. (1Pe 1:2)
Let no one deceive us (1Jn 3:7): those in Christ have received Him as He truly is, as both Savior and Lord. (Jn 1:12) Those who carelessly and willfully disobey Him as a manner of life don’t yet know Him. (1Jn 3:9)
The relentless assaults of false teachers require us to earnestly contend for the basics of godly faith as we engage each other to fight the good fight and lay hold on eternal life. (1Ti 6:12) God’s Word is unmistakably clear: those who don’t love Jesus Christ don’t belong to Him (1Co 16:22), and all who aren’t trying their best to honor and obey Him don’t love Him. (Jn 14:23)