I believe there are faithful Christians in the aforementioned denominations. I also believe there are unsaved folks attending our churches...often every week.
Salvation is far simpler than we make it out to be.
Luke 23:40-43 (KJV)
40 But the other answering rebuked him, saying, Dost not thou fear God, seeing thou art in the same condemnation?
41 And we indeed justly; for we receive the due reward of our deeds: but this man hath done nothing amiss.
42 And he said unto Jesus, Lord, remember me when thou comest into thy kingdom.
43 And Jesus said unto him, Verily I say unto thee, Today shalt thou be with me in paradise.
These verses often come to mind, when I read discussions such as this one.
Salvation comes during that moment in time when a person:
9 That if thou shalt confess with thy mouth the Lord Jesus, and shalt believe in thine heart that God hath raised him from the dead, thou shalt be saved. Romans 10:9 (KJV)
If that moment in time for any person doesn't come about, then they aren't saved, regardless of the demonination, whether Catholics, Coptic Christians, or Baptists.
Lord, remember me.