Paul wrote, "Therefore by the deeds of the law there shall no flesh be justified in his sight: for by the law is the knowledge of sin" Romans 3:20.
We have to be careful here, because Paul is talking about works of the flesh, and he did not refer to this as being religious.
People today use the term "being religious" to describe legalism. I don't mind this so much in it's proper context, but when it isn't in context you can find yourself disagreeing with scripture, or at the least, causing confusion.
What is a work of the law? A work of the law is any religious thing that one might do.
Nope, that is an incorrect statement.
James 1:26 If anyone among you thinks he is religious, and does not bridle his tongue but deceives his own heart, this one’s religion is useless.
Here James uses the term "religious" to explain that a religious person is expected to control his tongue, or his religion is worthless. And so the opposite of that is, a person is religious, and their religion is worth something if they live holy.
James 1:27 Pure and undefiled religion before God and the Father is this: to visit orphans and widows in their trouble, and to keep oneself unspotted from the world.
And so James explains that a religious person will do things. And so your statement describing a religious person is at best confused, because you need to be more accurate explaining what you mean,
The Pharisees came up with over 600 laws and rules for holy living called the Torah.
Salvation always has been and always will be by grace through faith. What we do or what we become does not save us. We are saved by the doing and the dying of Jesus, plus NOTHING.
Again this is confused. The faith part is very important. For example, there are places where someone will be faced with the fact that faith in Jesus may lead to them being tortured or killed. Or, faith may require a domestic sacrifice.
Here are some of the "YOU MUST" religions.
CALVINISM: YOU MUST be predestinated or you will not be saved.
But this is different from the legalistic point raised above.
CATHOLICISM: YOU MUST be baptized into the Catholic church or you will not be saved.
CHURCH OF CHRIST: YOU MUST be baptized in water or you will not be saved.
This is very true.
PENTECOSTALISM: YOU MUST speak in tongues.
Very few pentecostals believe this. Only extreme groups.
SEVENTH DAY ADVENTIST: You MUST be baptized in water.
SDAism is a cult.
BAPTIST: YOU MUST be baptized in water.
Water baptism is not a requirement for salvation, but it is something that Jesus wanted every believer to do. If people decided not to be baptized, it wouldnt say much about their salvation, would it?
Peter said, "can anyone forbid water, that these should not be baptized?" Interesting question. Their are movements today like hyperdispensationilsts who are forbidding water.
All religions teach that YOU MUST do something to become a member of their church. YOU MUST obey and follow the rules and the laws of their church whatever they might be.
Not to be saved.
This is the exact thing that Paul taught against.
Laws, rules and conditions for membership into a church is a work of the law. The only condition for membership into any church should be, "Do you have faith in Christ?" On that and on that alone, should be the only condition for membership into any church.
We have to be careful with people who claim to be Christian, but deny the faith with their lifestyle, as this can be a poor witness for the church.