I would talk to grandma.
Actually I think I will have quite some quarrels with my mother on the matter when my time comes to have children, as she is religious...

If I were you, I would tell your son to show respect by not leaving. But I can tell him to do a subtle way: just put his point finger over his middle finger.

Fair play to the lad for walking out instead of kicking off, shows great powers of restraint. Diametrically opposed to grandma's refusal to take the very obvious hints, insisting on 'returning' the propaganda they so obviously did not want anything to do with!

My late partner was from Iran (Moslem). Her mother fostered her to question everything. I heard so many stories of my partner bringing notes home from the teachers saying how rude she was for questioning religion. Her mother just nodded and said she would take care of it, but never did and her daughter was a lifelong atheist. She thought religion was silly and didn't understand how people could believe such nonsense. When the revolution came in 1979 she saw what religion can do to a country.

To me to go along to get along is, in many cases wrong. Look where it has gotten us. Kudos for your kids to have the guts to stand up for their convictions.

I recommend that people, on this site, join the Freedom From Religion Foundation. There are many instances of young people having to face discrimination because they refused to cave in when others tried to push their religious beliefs on them.

Respect is a two-way street.

I got some blowback about my daughter not respecting her elders and after thinking about the situation I stood with my daughter. It's only my opinion but it sounds like your kids have as much respect for their grandma as she has for them. If they disrespect her in other ways that would be a different matter. It's your mom, I presume, and your kids so none of us can tell you what to do but good luck.

use them as door stops and let it go.

I would donate the books to a church or library and tell Grandma to respect your and your kids beliefs.

I would talk to him about being respectful, as well as the grandma. Talking to her may stir up trouble though, so be ready for that. As for the books? Put em away on a book shelf or give them to someone who actually wants the books.

Teach them to be respectful of people that are respectful and that trying to force a book or belief system on people is not respectful.

“Grandma, I know it’s rude to walk away while you’re praying, but it’s rude for you to try to force your beliefs on others”...

I think they should pray that their grandma still has the receipt so that they can return them and get them something more meaningful - such as a book on evolution

You have smart kids-they know their own minds. Didn't say their ages-over 13 they're fine.

My opinion only, it's always a good idea to teach respect and tolerance. The little one could have sat with his hands in his lap and allow the others to pray. I never taught my children that believing is a bad thing. It's a very personal decision and should be respected. But it kind of sounds like Grandma could use that lesson, too. As far as the books are concerned, those books belong to your children. They should decide what happens to them and you should respect that decision. Again, just my 2 cents!

I think you should talk to GRANDMA about being respectful. So damn tired of holy rollers makiing all the rules and shaming those of us who choose not to participate in the same old crap.

No let it go, I do not know his age but standing for what you believe is a good thing. No matter what age.

Actually, I think you should speak to grandma about calling children names. She should know better. If not, enlighten her.

Sounds like both he AND Grandma are in need of a discussion ...