Religious “Legalism” with a capital “L” is heresy.
It’s the belief that one’s personal virtue and obedience to religious norms or standards merits God’s favor and/or salvation. This “do-it-yourself” religion is antithetical to the gospel of Christ and the Bible’s grace-based religion.
“For by grace you have been saved through faith,” writes the Apostle Paul. He goes on to remark, “This is not your own doing; it is the gift of God.” (Eph 2:8) When asked what deeds God requires of men as a condition for eternal life, Jesus surprised his audience with the reply, “This is the work of God, that you believe in Him whom He has sent.” (John 6:29; see also John 3:16, 36; Acts 4:12; 16:30-31; Rom 10:9-13)
I used to think that I could earn God’s favor and salvation on the basis of my inherent virtue and good works. Of course, I admitted I wasn’t perfect. But I foolishly presumed that my good deeds would somehow outweigh my bad deeds.
In this respect, I thought and behaved much like the Pharisees, scribes, and Jewish people of Jesus’ day who trusted in their own inherent virtue and religious performance to merit their acceptance before God (Matt 5:20; Luke 16:14-15; 18:9-12, 14; Rom 10:1-3).
Thankfully, God helped me realize that my sinfulness was heart-deep (Gen 6:5; Jer 17:9; Matt 15:19-20) and that the best of my moral or religious deeds were worthless for earning His favor (Isa 64:6; Rom 3:20; Phil 3:4-9). By His saving grace, I repented of my sin and self-righteousness, placing my confidence and hope in the person and work of Jesus Christ alone.
That’s when “Bob the Legalist” died.
Conversion freed me from the penalty and dominion of sin, but sinful tendencies were not completely eradicated from my heart. I still struggled with some of the old tendencies of “Bob the Legalist.” Though I was no longer a Legalist, I still tended at times to think and behave like a legalist (lower-case “l”).
Elevating My Own Opinions
Without biblical warrant, I tended to view certain practices as “wrong” and Christians who endorsed or practiced them as “worldly.” Instead of basing my understanding of “worldliness” on the teaching of Scripture (John 2:15-17), I based it largely on my own preferences, prejudices, and personal standards. As a result, I sometimes condemned what the Bible doesn’t condemn and disapproved of other Christians whom God approves (Ezek 13:22; Rom 14:3-4).
Looking Down at Others
I also had a tendency to be hypercritical of Christians and churches that didn’t share all my beliefs and convictions – while remaining to some degree blind to my own remaining sins and weaknesses (Matt 7:1-5). Instead of focusing primarily on the central truths of the gospel, I was overly preoccupied with beliefs and practices that distinguished me from all other Christians and exalted those beliefs and practices to a place of unwarranted priority (Matt 23:23). As a result, I so focused on minute orthodoxy that I lost sight of brotherly love (Rev 2:2-4) and humility (1 Cor 4:7).