The New Testament (NT) makes many references to Mosaic Law, Torah, repeating and reinforcing its commands. The Tanach (Old Testament) was the only inspired scripture in the days of the Apostles, who were zealous of Torah their entire lives (Ac 21:20); they quoted it often in their teaching, and based all of their doctrine upon it.
Some seeking to diminish the relevance of Torah today claim that only commands specifically called out in the NT are still relevant. This standard is, of course, arbitrarily imposed on scripture: it is not in scripture itself. Still, it’s enticing to those looking to ignore some part of Torah (Ps 119:6), unaware of the eternal consequences. (Mt 5:19)
The primary problem with this view is that Christ openly refutes it early in His earthly ministry, explicitly addressing this error and affirming the eternal validity and relevance of Torah in precise, unmistakable language. (17-18) Once we understand this, if we’re observant, we find the entire Tenach reinforced and upheld by apostolic teaching.
For example, Paul says we’re bound by Mosaic divorce laws (Ro 7:2-3, 1Co 7:39), and claims a law governing the treatment of oxen is intended for us all, instructing us in financing Christian ministry. (1Co 9:9-10) He commands us to avoid all uncleanness (Ep 5:3), which must include the types of uncleanness specified in Leviticus, and Peter appeals to gentile believers to live in holiness (1Pe_1:15-16) because God commands Israel to be holy. (Le 20:7)
Paul tells us the entire Tenach is given to thoroughly equip all believers to live godly lives. (2Ti 3:16-17), so the idea that some part of Torah is obsolete, or no longer relevant, is foreign to apostolic thinking; they rejected this error decisively and consistently (Ac 21:24), along with the apostle Paul. (Ro 3:31) The error took hold in the Church many decades after the apostles moved on to Glory, and persists quite widely until the present.
Even so, Paul asserts that Torah will be the universal standard by which Christ shall judge the world, stating that the entire world remains under its authority. (Ro 3:19) Yet, he also asserts that believers are under grace and not under Torah (Ro 6:14), raising the ultimate question: is the believer then free to sin, to violate Torah?
This is equivalent to asking if we’re required to stay within the protective guardrails of a canyon’s precipitous overlook. Only those with a death wish would even ask the question.
The answer is obvious, and Paul answers clearly: No (15), we’re not free to sin. Believers are not only obligated to obey Torah (16), we’re given a new nature which delights in Torah (7:22) and enables us to obey it. (Ro 5:21)