Show the christians tolerance?
What tolerance has the church shown?
Tolerance for homosexuality, women's rights?
What tolerance.
The catholic church's rape of young boys (and girls), support of nazi ethnic cleansing? Condom use in Africa?
What tolerance.
I disagree entirely with your assumption that I should automatically show any tolerance to these bullshit organizations.
In fact I think your half-hearted support of your grandfathers beliefs is a lie. Both to him and yourself. I'm glad that you have a comfy feel-good relationship with your granddad. Try this... tell him what you really think and then see what his response is. I suspect it won't be as touchy-feely afterward.
This is your responsibility.
Religious moderates fully support religious extremism and provide the mechanism for their continuing hypocrisy & dogma. Be it in the middle-east, here in America and every little corner of the world.
Tolerance is not what religious organizations need. It's exactly the opposite.