Biblical Translation Copyright disclaimers
With regards to Orthodox ‘Mesaianic Judaism’ perhaps this is best described as a search term for ‘Christianity in it’s correct context’.
Peaceably, many ‘mainstream’ Christians here may see such a concept as legalistic and ‘under the law’.
With regard to the Law of Moses matter, to clarify, perhaps it could be best explained as this:
Under vs. Uphold
To be under the law, means that a person does not believe in Christ, and instead, is really relying on their own good deeds for a ruling which is ideally favourable, when they are judged.
This approach is not conducive of everlasting life without end (ref. Deuteronomy 28:15 , Galatians 3:10, Isaiah 28:22).
An article which explains what it means if a person is seeking to be ‘under the law’, can be found here. It features Galatians 4:21;
‘Tell me, you who desire to be under the law…’
(Galatians 4:21 ESV)
To uphold the law, means a person does believe in the risen Lord Jesus Christ, and is believing for saving grace at judgement from God through Christ – as they observe the Law of Moses.
This approach means everlasting life without end (ref. Isaiah 28:16, Ephesians 2:20, John 3:16).
For we hold that one is justified by faith apart from works of the law.
Do we then overthrow the law by this faith? By no means! On the contrary, we uphold the law.
(Romans 3:28, 3:31 ESV)