Christians follow Jesus.
The problem comes in when anyone follows anyone else’s *interpretations*, even those of the Catholic church.
What your questions demonstrate is faith in a works based belief system. It’s all based on following someone else’s teachings about what they should do and not do. That’s where factions and denominationalism comes in, the us vs. them, mentality. They don’t do what we do, therefore they’re not saved.
But salvation is not based on works, because by the works of the law, no one shall be justified. The law was put in charge to lead us to Christ, to show us what God’s standards are so that we can see our need for a savior. (Galatians 2 & 3)
The righteous shall live by faith. Good works are prepared in advance for us to walk in and do them, not to save us but to demonstrate to the world the power of God in our lives, to minister to the hurting and needy, to overcome evil with good, and, ultimately, to glorify God.
The Jews thought that obeying the Law to the letter saved them, so they took the Law God gave Moses and added to it. Jesus condemned their traditions of men that only further burdened men. Paul himself said that for all his flawless keeping of the Law, he counted it all loss for the sake of knowing Christ and being found in Him, not having his own righteousness but having the righteousness of Christ credited to his account, so that Paul himself did not have to keep the law.
If someone who could keep the law as well as Paul did could not be saved by it, then nobody can.
Not all works are the same. Works done to attempt to obtain Salvation without Jesus, such as circumcision and observing Kosher laws, are indeed ineffective. However, as St. James wrote, faith without the works of corporeal and divine mercy as characterized in the Beatitudes, is indeed dead.
Peace be with you,