If he asks, tell him. Otherwise, since he already knows that you are agnostic, forget about it. My wife is a devout Catholic and knows that I am an atheist. We each respect the other's right to believe as we see fit.

I figure if someone is that important in my life, I want them to know my views on pretty much everything. And I want to know their views, too, and their views about my views, and… down the rabbit hole we go. I suspect if he's okay with your agnosticism and doesn't spend every waking moment trying to convince you or drag you off to church, he'd be okay with your atheism — but only you can make that determination. Good luck to you.

Id tell him and let the chips fall - truth is on your side

I would venture a guess that most ‘agnostics’ are actually atheists. What definition of atheist are you using?

My ex wife knew, I didn't really hide it. It only came out sometimes when we were in an argument. She'd make snippy comments about my lack of religion. She considers me atheist and I don't mind OTOH, I consider myself 20% agnostic(I know, I know). I'm not a militant -is there such a thing?- agnostic, but I never did mind talking about it. Especially to snooty religious people
My favorite phrase when watching tv is when someone thanks god for something-I just can't help saying, "god had nothing to do with it!", Lol.
My daughters started finding it amusing as they got older. Anyway, my 2c.
There's no way I could not talk about it. How long have you been married?

This

While my initial reaction is much the same as everyone else’s...live and let live, ignore it and enjoy it, different strokes for different folks etc., I believe there are situations in life where this could def cause trouble for you. For instance, if you have children and there is a disagreement on how to raise them. I honestly believe that it is important to be truthful with one another about your beliefs. It can prevent major issues down the road and give you a base understanding of one another that allows for compromise on both sides...not just on yours. I hope this helps?

It's difficult, because most christians are encouraged to "spread the word" and bring other people to believe. If someone is to follow this, or even just think about it, then it must come with greater pressure when it's someone in their own family. If this is a big deal for him, then you're presenting your atheism to him would be a direct challenge to his faith. I don't know the consequences of that, but you did ask why you might not want to...

In my opinion, and in my experience, such a thing should not be hidden from one's partner in life. At some point, he needs to know, if he doesn't already suspect, what's in your heart and mind (philosophical locations, not religious ones). I have always been partial to conversation. The more, the better. Perhaps it begins with Socratic questions, or a discussion about something you read or heard on the news. Are both of you 'churched?' That can make a significant difference.

How important is it to you to tell him? If you love him do you want to risk losing him over discussions of an imaginary man in the sky? True love is a real jewel. An imaginary person is nothing. I tend to "preach atheism" but unless you find that as your calling I would simply be happy and let it go. I'm not telling you to lie to him. I'm just saying don't rock the boat.

My wife and I of 42 years have agreed not to discuss religion as she’s a believer and I’m a strong atheist. My 2 children have asked me not to discuss my lack of belief with my grandchildren and my 6 year old grandson is concerned about me going to hell but I tell him you can’t go somewhere that doesn’t exist. Maybe someday he’ll see the light.

You can't because you are afraid of how he will react.
Let sleeping dogs lie.
Avoid the subject, he woudl have some idea, and he is letting things sit.
I would not get into it at all.
A good relationship is too hard to come by,
don't risk it.

I don't think there are any easy answers. Honesty is important in a relationship, but that doesn't mean you need to share every single thought with him. Just be yourself, professing doubts is certainly honest and give your reasons why, ask scencere thought provoking questions. And he can always pray for you (that is only a little tongue in cheek). I believe there are some resources online that you can go to to see how others have handled it. Shame or Not, fear can be paralyzing. Belief comes in a full spectrum...from those who say I am a Christian, but never go to church or haven't even really given it much thought.... to those that are ministers or bible thumping congregants that go to church 3 times a week.

I would ask what flavor of religious is he?

And why does he not know what you believe already?

Some reglious folk are more tolerant than others.

I get the feeling you know your own answer already. There is some reason you've never had this discussion.

If you aren't ashamed, then tell him.

I wouldn't, you never know how believers are going to react until you tell them, then it's too late. Why risk it, unless he askes you straight out, then I would tell him.

Let sleeping dogs lie...if he already knows you have doubts (agnostic) and hasn't tried to drag you back into a church, he is obviously fine with things as they are...unless you want to drag him into your "church? Not cool!

Perhaps it's because religious people are so offended by us. In my experience once they find out your an atheist they treat you as they expect you to treat them. Maybe your afraid to shatter his belief that you can be saved.

I am in the same boat with my daughters. They know I have doubts, but do not know that I am a full-blown atheist. In actuality, atheists are also agnostic as it cannot be known whether some sort of god-force exists in the universe--we simply do not believe that one does. I suppose, if you feel a strong need to tell him, you could word it that way: admit that it cannot be known, but that you simply see no evidence of one. And, if actual evidence should be provided, you will give it due consideration.

Don't take the fundamentistal pledge about believing. There are like 5000 known mistakes in the Bible and more be uncovered every day as well as new findings which concede with the other findings in the early 1900. Its nothing to be guilty about and having a healthy skepticism is a very normal and healthy mental attribute. You can reveiw all of the Sexual Misconducts that exists in all religions as well as fraudulent representations. Along with the Catholic Church you can review Jimmy Swaggert, Jim and Tammy Baker and even Billy Graham who at one time realized he couldn't get out of it because of all the money he was making. Check out Joel Olsteen on that one also and tell me what his religion is truly about. The Inquisition is also of notable study and then go to the Scholars like Bart Erhman, The Atheist Experience which is a weekly radio show as well as a website on You Tube to soothe your guilt. Even You Tube the Gospels and see what I'm talking about and a host of scholars to debate what is rightfully historic and documented which is something most of the Bible is not.

You’ve told NO ONE you are atheist?!?

So...is he a Gnostic Theist or an Agnostic Theist? I assume you are an Agnostic Atheist? Or are you an Agnostic Theist as well? Maybe you aren’t as different as you think.

Well by default being so close means you have to come clean doesnt it?

I have always had Frank discussions with any serious relationship married or otherwise about my religious beliefs. I do this in a very non-judgemental way concerning their beliefs. I won't tell a religious person but they are wrong or that there is anything wrong with their beliefs. I simply explain to them why it is not for me why I believe what I believe and with little exception they are very accepting of my atheism. It is all a matter of how you approach it. Be supportive of his beliefs asked that he not be judgemental about yours.