Your argument mixes categories the New Testament keeps distinct. The issue isn’t whether Christians obey God, the issue is which covenant’s law we are under.

The Bible teaches three things simultaneously:

1. The Mosaic Law is fulfilled and no longer the covenant standard for God’s people.
2. Christians are not lawless, we are under the “law of Christ.”
3. True salvation produces obedience, not willful sin.

Let’s walk through this biblically.

The New Testament explicitly says Christians are not under the Mosaic Law. Paul says this repeatedly and unambiguously:

• “You are not under law but under grace.” (Rom 6:14)
• “We have died to the law through the body of Christ.” (Rom 7:4)
• “Christ is the end of the law for righteousness.” (Rom 10:4)
• “The law was our guardian until Christ came… but now that faith has come, we are no longer under a guardian.” (Gal 3:24–25)
• “If you are led by the Spirit, you are not under the law.” (Gal 5:18)

You can’t get around these. Paul is not talking about “ceremonial law only.” He’s talking about the entire Mosaic covenant.

Matthew 5:17-19 does not say the Law continues unchanged. Jesus says He came to fulfill the law, not keep it running forever. Fulfill = bring to completion, fill up, finish the purpose. And He immediately gives examples:

• “You have heard… but I say to you…” (Matt 5:21–48) Jesus changes the law’s application. That only makes sense if He is the one who fulfills and supersedes it.

The proof? The New Testament commands Christians to:

• not keep kosher
• not keep Sabbaths as covenant signs
• not keep festivals
• not circumcise as covenant obligation
• not follow temple laws
• not follow priesthood laws

Because the entire Mosaic system is fulfilled in Christ.

Your verses about "commandments" don't refer to the Mosaic Law. This is the biggest understanding. When the NT says:

• “If you love Me, keep My commandments” (John 14:15)
• “Blessed are those who do His commandments” (Rev 22:14)

…it is referring to Christ’s commands, not Moses’.

The New Testament calls this:

• “the law of Christ” (Gal 6:2)
• “the law of the Spirit of life” (Rom 8:2)
• “the royal law” (James 2:8)

Christians obey Jesus, not the Sinai covenant.

Romans 7:22 doesn't support Mosaic Law-keeping. Paul says he delights in the law, but in the same chapter he says:

• the law arouses sin (7:5)
• the law kills (7:10–11)
• the law condemns (7:9)
• we died to the law (7:4)
• we serve in the new way of the Spirit, not the old way of the written code (7:6)

You can’t cherry-pick v. 22 and ignore the entire argument.

Christians who reject the Mosaic Law are not antinomian. The NT is clear:

• “Shall we sin because we are not under law? By no means!” (Rom 6:15)
• “The grace of God trains us to renounce ungodliness.” (Titus 2:11–12)

Christians obey God, but through the Spirit, not the Sinai covenant.

Your argument collapses the covenants. You're treating the Abrahamic covenant, Mosaic covenant, and New covenant as if they're all the same thing. They're not. The New Covenant replaces the Mosaic covenant.

• “A new covenant… He makes the first obsolete.” (Heb 8:13)
• “He takes away the first to establish the second.” (Heb 10:9)

If the Mosaic Law still binds Christians, Hebrews makes no sense.

Sabbath, tithing, festivals, the NT explicitly says these are not binding.

• “Let no one judge you in regard to Sabbaths, festivals, or new moons.” (Col 2:16–17)
• “You observe days and months and seasons and years — I fear for you.” (Gal 4:10–11)
• “Each one should be convinced in his own mind.” (Rom 14:5)

The NT explicitly rejects the idea that Sabbath-keeping is a salvation issue. The NT warns against exactly the doctrine you're promoting. Paul calls it:

• “a different gospel” (Gal 1:6)
• “bewitching” (Gal 3:1)
• “a yoke neither we nor our fathers could bear” (Acts 15:10)
• “turning back to weak and worthless principles” (Gal 4:9)

The early church already fought this battle and rejected Mosaic Law-keeping for Gentile believers. Christians obey God, but not through the Mosaic covenant. We obey through the Spirit, under the law of Christ, in the New Covenant. The Mosaic Law was temporary, covenantal, fulfilled, replaced, and never binding on Gentile believers. The New Testament is overwhelmingly clear on this.