I don't believe this at all.
Hebrews 10:25) not forsaking the gathering of ourselves together, as some have the custom, but encouraging one another, and all the more so as YOU behold the day drawing near.
We were told to keep the Sabbath day holy. That doesn't mean we have to go to church? Some people prefer to pray alone,or with family inside your own home? Going to church is not in the bible. It's not something God is demanding us to do. So..why are people still saying it's a sin?