People who rigorously observe the sabbath are putting themselves back under the Mosaic law, which is antithetical to the freedom in Christ
Jesus came to free us from sin....
Not partly
Completly.
He paid the price.
But He also wants to transform us and create a new heart within us.
Being a slave to sin is what Jesus wants to free us from.
We can't do it ourself and it requires faith in Jesus.
But Jesus does not want to pay for our sins so we can keep sinning..
Rom 5:20 Moreover the law entered, that the offence might abound. But where sin abounded, grace did much more abound: 21 That as sin hath reigned unto death, even so might grace reign through righteousness unto eternal life by Jesus Christ our Lord.
6:1 What shall we say then? Shall we continue in sin, that grace may abound? 2 God forbid. How shall we, that are dead to sin, live any longer therein? 3 Know ye not, that so many of us as were baptized into Jesus Christ were baptized into his death?
Freedom in Christ does not mean free to sin. It means free from sin. Jesus gives us the power to overcome.
1Jn 5:4 For whatsoever is born of God overcometh the world: and this is the victory that overcometh the world, even our faith.
2Pe 2:19 While they promise them liberty, they themselves are the servants of corruption: for of whom a man is overcome, of the same is he brought in bondage. 20 For if after they have escaped the pollutions of the world through the knowledge of the Lord and Saviour Jesus Christ, they are again entangled therein, and overcome, the latter end is worse with them than the beginning.