All my love and condolences for you two awesome guys, Guy and Mark, in this, your time of loss. I truly hope that you guys get through this with your heads held high. I'm sure that your dad was an awesome dad and I know that he loved you very, very much.
I would offer spiritual advice, but you know that I'm not spiritual. However, I can say, at the very least, that your old man is not in any pain any more.
Again, all my love to y'all and your family.