I agree completly. However when you love someone you want to show them you love them. That is where the ten commandments come in. It's like telling God we love him by following them. Also they can act as guiderails. Because without them things can sometimes get confusing.
What if you are in a situation where you broke something and you know you will get in trouble if your mom finds out? You could easily lie but the ten commandments say not to lie. So you are presented with a choice of lie or don't lie. If you choose to lie that means you are choosing to sin and that is bad. But if you choose to not lie that is really good. It doesn't make you rightious or earn you any brownie points with God but you know you did the right thing in that instance. I repeat, this action does not save you from the fire of hell but it shows God you are trying. It shows your heart. Not only that but it shows other people your heart as well. By being obedient to God it can't keep you in line all day every day but it can keep your heart in the right place.
Also if lying is wrong and it is part of the Ten commandments, and it was wrong in the old testament and is still wronf today, along with all the other commandments what makes the sabbath any different? If the old covenant was done away with, we should be free to worship other gods and to lie, murder and do whatever because we are "covered by grace".
Can I ask you? If you want to look to the literal letter of the law, does this include Christ's literal commandments? Are they as important as OT law? If they are, how do you find obeying those literal commands in the beatitudes, and the rest of Christ's teachings?
IE
Don't invite friends and family home for a meal but rather the lame, blind, poor, beggars so you may receive your reward in Heaven.
If you fast make sure no one knows you fast or accept you are a hypocrite.
If anyone steals anything of yours, give them more besides with nothing but love in your heart for them
Don't short change yourself.
It is not enough just to not commit adultery. If you as much as look at another with lust in your eye you have already committed adultery with them in your heart.
It is not enough just to say you do not murder, if you get angry with your brother or sister you are subject to judgement.
You could perfectly obey the ten commandments(if that were possible) and still be cast into hell. For there is nothing in them about forgiving others. But Jesus said, if you do not forgive your brother your father in Heaven will not forgive you.
The yardstick is NOT the Ten Commandments. Try and follow the literal letter of Christ's teachings in the beatitudes. If you do, you will soon look away from the literal letter and to Christ-if you are sincere