I am not playing the "what if" game with you or anybody.  I don't know all the different ways Catholics refuse to hold some particular beliefs and yet still cling to the practice of the faith or to their identification with the faith.  I do believe that an examined faith includes doubt and that faith despite doubt is what religion is all about.  I also believe that what we learned about God, His love, morality, the dignity of each person created in the image of God within Catholicism - all that somehow works its way inside of us and guides us to live a better life than we otherwise would live and experience.   It isn't about keeping the rules - it is about how you love and respect and care for your brothers and sisters.  

If someone denies the divinity of Christ, love them anyway.  Maybe that person has other ways of living out the message of loving God and self and neighbor that you can learn from or be inspired by.  We are not robots.