I am starting to become really frustrated with pretending to be Christian. I now see all the flaws and fallacies in what friends and family say when they talk about god. I try to be careful with what I say, trying to avoid directly saying "I believe," and also being careful with the questions I ask.

I've been considering coming out to my family and friends about my atheism, I just don't know how to go about doing this. If you have told your family, I would like to know how you did that and what reactions and responses you received. I don't want to be caught off guard with any of the responses I receive.
I want to be well prepared for this, I would like to know if there is any information or any particular arguments I should have a rebuttal for, if so, could you please recommend some good resources that I could access. Recently I've been watching a lot of Matt Dillahunty and have learnt a lot from him.

Something I will need to keep in mind when coming out as atheist is that my grandfather is currently getting his masters in theology, so I expect to get into many debates with him about this, I doubt I will get into many debates with the rest of my family. Because of this, I am kind of wary about how I go about coming out and what I should know before doing it.

I think this is something that is really important for me to do and I don't want to hide what I believe, or lack of, for much longer. Thanks in advance for any advice.