It seems apparent that if Christians read "All Scripture is inspired by God and profitable for teaching, for reproof, for correction, for training in righteousness; so that the man of God may be adequate, equipped for every good work." (2 Timothy 3:16-17) and take from it that 'Mosaic law' is not a necessary requirement but rather is optional material, can only be attributed to viewing the Torah much differently than the “Old Testament Saints” did.
I found several explanations for how these people viewed the Torah in Bible times but here are a few. One is that they perceived obedience to the law as an expression of covenant relationship--obey the voice of God, and this obedience to the law was perceived as the external expression of an inward disposition of fear and faith in God and love for God. Another one I found most profound is that being able to hear what the God of Israel wanted was considered a unique privilege compared to the gods of the nations who didn't speak – pagan religions. They were thankful to know with clarity and confidence what God wanted for their lives. This is so sadly lacking today where professing Christians act as if God is supposed to do their will simply because they claim to be Christians. That is a pitiful state of affairs. One more is that while they believed the commandments were achievable, it was also understood that God, recognizing their propensity to sin, had provided a means for forgiveness and communion through the sacrificial and ceremonial ritual. And those physical rituals of sacrifice flow seamlessly into the doctrine of the New Testament where we are the temple now, the renewed covenant!
People like to say the old and new covenants are completely separate but Jeremiah looks forward to a time when physical Israel and spiritual Israel will be as a complete and balanced entity, when all will love God and make it obvious by their lives that his Torah has been written on their hearts.
Jeremiah 31:31-34: "Here, the days are coming," says ADONAI, "when I will make a new covenant with the house of Isra'el and with the house of Y'hudah.
32 It will not be like the covenant I made with their fathers on the day I took them by their hand and brought them out of the land of Egypt; because they, for their part, violated my covenant, even though I, for my part, was a husband to them," says ADONAI.
33 "For this is the covenant I will make with the house of Isra'el after those days," says ADONAI: "I will put my Torah within them and write it on their hearts; I will be their God, and they will be my people.
34 No longer will any of them teach his fellow community member or his brother, 'Know ADONAI'; for all will know me, from the least of them to the greatest; because I will forgive their wickednesses and remember their sins no more."
One last observation before ending this post – I have been told by professing Christians that they don’t need to study because the Holy Spirit writes the Torah on their hearts. This is an obvious blatant untruth because they can’t tell me anything the Torah says except ‘the ten commandments’. If it was in their hearts, they would not fight against those who respect and revere the Torah and they would know a whole lot more than the ten commandments.