Brian -
I too lost my father after establishing a relationship with a man that was not the father that he should have been or that I dreamed of having. I held my father's hand and spoke to him as he passed. I relive those final moments daily. I live them in my waking thoughts as well as my dreams. There has not been a day go by in four(4) years that I have not replayed those moments in my mind. I tell you this in hope that you will not live with the regret that I now live with.
lead your father to Christ. There is no greater gift that you can give him then eternal life. Say this preyer with him. "Lord, I confess to you that I am a sinner. I know that I deserve God's penalty for sin, but I believe that Jesus died in my place and rose again from the dead. In the best way that I know how, I ask you to forgive my sin, come into my life, and make heaven my everlasting home. Help me to live for You from this day forward. In Jesus' name, Amen."
That is the prayer of "Salvation". They were the words that I wish I had spoken while holding my dying father's hand. I failed my father as he failed me and I will regret that for the rest of my life.
I have prayed for you and your father...
Mark