About 20 years old I gave up my son for adoption. My dad said it was a closed adoption, but he knows the family that adopted him and they all go to the same church. My son is now 20 years old and my father won't give me information any on him. I do know what his first name is Christopher. Is this a hapless case to try and find him or is there a chase to find my son after 20 years?

Since he is 20 he should be able to have a say in if he wants to met you. The thing is that since it was a closed adoption I don't think you can just walk up to him and introduce yourself.
Your dad since he knows them should be able to act as a middle man and ask the parents about his feelings of meeting you--if they even told him he was adopted.

OK, you go to your dads church and see who is in their 20's and name is chritopher, that would be about the easiest thing to find as I have ever heard.

IF you do what Fr_Chuck suggested you need to remain 'anonymous' basically.
I was going to suggest that but thought about the impact it could possibly have
Like if your dad creates a scene or the family never told him he was adopted.
That can *traumatize a kid to find out he was 'lied to' all those years.
Plus even if he does know about you it could upset him if he never wants to see you.
You have to go through a third party somebody to feel it all out.

about 20 years old i gave up my son for adoption. My dad said it was a closed adoption, but he knows the family that adopted him and they all go to the same church. My son is now 20 years old and my father wont give me information any on him. I do know what his first name is Christopher. Is this a hapless case to try and find him or is there a chase to find my son after 20 years?
Join a search and support group online, along with contacting your church. Most people need guidance in their search process. Read as much material about this issue as possible. Get many points of views. Both positive and negative and it will help guide you in your journey.