"Dearly Beloved, as we ponder John's eternity in Hell, let us thank God for giving him countless opportunities each day of John's life to repent and receive Christ."
Seriously, though, I think one can be honest while being tactful.
The funeral isn't really the time to judge the deceased. If it were me, I'd just give the Gospel and let God do with that what He will.
Excuse me???????? You are saying I am headed to Hell?