Tell him you just cannot do that as you are far too hurt by his death.

If you like the father just say you will pray in private but not go to bible study,that is what I would do

Tell him to mourn in his way and you will mourn in your way but his way is not your way.

If I were in that situation, I would ask for evidence that "the bible stuff" is true. This usually has the effect of turning missionaries away from my door. It may also sow a seed of doubt, and help religionists discover that there is no credible evidence.

Tell him no

I'm very sorry; I'm sure you're hurting, and so is he.

But, just as you would be wrong to push his father to accept that there is no afterlife, his father is wrong to push you to accept his version of it. But there is a gentle, polite solution! "I don't wish to pray," is perfectly acceptable.

It may be helpful to realize that prayer and talk of heaven is just the LANGUAGE he uses to talk about his pain. Remember that even if the language is obnoxious, the pain is very real.

And you can still deal with that pain in a compassionate way! After declining to pray, you could steer the conversation toward recalling fond memories of the deceased. Talk about what he liked, tell some funny stories. At first, these memories should be positive. Later on, you may wish to include some unpleasant memories as well. I say this not to be cruel, nor even to hold him to account for his infidelity (though that would be fair,) but to emphasize that grief does not have to be all rosy and perfect. People are messy, grief is messy, but messiness is honest. And honesty will heal you both more completely.

When you're ready, I highly recommend The Grief Recovery Handbook by John James and Russell Friedman. This is a nonreligious step-by-step approach to recovery from grief, and I've found it SO MUCH MORE HELPFUL than the standard tripe that passes for grief counsel. This is a book meant to be read with a partner; that partner in grief could very well be your ex's father.

Should assume you have kids? Why do you feel obligated to interact with him anymore at all? Not to be cold and heartless, but can't you just not talk to him? Maybe I'm a jerk.

Just tell him your sorry about his son but will pass on the Bible study.

Very sorry for your loss. Maybe just be honest with the father. Grief effects each of us differently. Do what you can to help each other through this time. I lost my first wife at 33, trust me it's nice to have someone to go through it with you. Even though the two of you don't have the same beliefs. I hope you find some comfort here in the agnostic.com community. I know it hurts, but with time and friends to lean on it will get better... I promise.

A few points;
1, Sorry about your loss but it seems that you would have been splitting up with him sooner or later anyway
2, Your beliefs and mental health are paramount here, nobody else.
3, Of course, you do not want to deliberately hurt his father but if he already knows about your non-belief then it is he, not you that is overstepping the mark.
4, Given the situation, any kind of relationship with his dad only has a short shelf-life. As time goes by and you heal, you will inevitably move on. You may or may not want to keep him as a friend or just a number on your phone with an X-mas card each year. But he will gradually fade out of your life and that is a naturally good thing. Bottom line is if he does get hurt then you can walk away not only with a clear conscience but with little or no consequences.

This is a very difficult time for you and it will require some strength. Self-preservation is not selfish, it is necessary. Look after yourself and things will get better with time

His father is grieving and wants you to be involved in his loss. The loss is also yours, but your's is also quite different. You have lost all that love, family, trust and whatever else you had personally, as well as him physically.
I would make sure your father in law understands your beliefs and that for you the bible gives no succor, no healing.

Be honest with him... It's all you can do!

My condolences. I feel for you in this difficult situation. Sorry that on top of your loss, and pain you've already endured, that his dad is pressuring your this way. Your short description doesn't indicate if this is new behavior for him, or if he was always like that.

I would try to keep it as short as possible. Maybe something like, "I'm sorry for your loss as well, but i don't have the need for prayer". Or maybe a bit more direct "i don't share the same beliefs so praying and bible studies don't appeal to me". However you handle it good luck

You don't need to compromise yourself to placate his father, tell him you are mourning in your own way and he needs to do the same. You are allowing him to manipulate you by using grief as his tool. If his son was a liar and manipulator then he learnt it somewhere (potentially for dad) and he does not seem overly concerned about your feelings. Sometimes an instant guilt is better medicine than suffering in silence while someone uses you. Stay strong and do the right thing by you in this instance if you can find the strength. The problem with religion isn't the people who embrace it and use it as a tool to make their lives better, like spirituality, exercise or mindfulness, it's the people that attempt to inflict their beliefs on you regardless of the damage or discomfort that you may feel. You owe this man nothing, and yourself everything. Love yourself, find your peace and walk away from this person, you deserve more always.

I would say that, "what has meaning for you (him) does not have the same meaning for me, in fact just the opposite. I wish you whatever comfort there is to be had from your belief, but I must deal with the loss in a way my own worldview has with regard to death and dying. The belief in God or an afterlife is not a part of it."

Firm, but fair. One makes their own boundaries as needed.

Sorry for your loss and the uneccesarily added grief.

"I am sorry Mr. X, I hope you will understand but I'm really going to need some solitude to do my mourning the way that I need to do it".
And I wish you better choices in your future!

Sorry about your loss even with the issues. What do you tell the father? Tell him that each of us grieve in our own way and your preference is to grieve in private and not with him. That is what I've had to tell people sometimes.

The father is projecting his feelings & thoughts of his son on to you. Be compassionate but don't be indulgent. Be sad but don't be sorry.

I would be suggesting he get some of his christian church friends to pray with him and do bible study. I am sure they resent him not giving them the chance to do their christian duty. That you just really need to "move on" so you can let go of your pain, and not have to keep re-living the pain of his passing. Come on,,,you've paid your dues....get out of his nightmare.

I’d try to find good local group for him to join that might help him. I don’t know much about your local geography, but something like this: [namisantaclara.org]

The father should be an adult about it instead of trying to appease his god by trying to get you hooked. He just wants to control you like he did to his son. It would end bad for you...step clear away.

Don't answer the phone.

I would just say I’m sorry about your son but I’ll have to pass on the Bible study.

I’m a widower myself, and I’ve learned that as long as you don’t self medicate or hurt someone else, there’s really no wrong way to grieve. Your boyfriend’s father is using his religion to help him try to make sense of the loss you both, and that’s ok. You may find that you will be able to help each other get through this, so I would suggest that you go at least once. I hope you both find some peace.

Just tell him you are not a believer, so what if his feelings get hurt, why would that be your responsibility? Just say it politely and that's it. I he gets upset, that's his problem.