II Sam 12:22-23 (post-workout =P)

I often pray while I workout/run and as I prayed for grandfather, last night's reading of II Sam 12:22-23 occurred to me.

This is after the 1st son that Bathsheba birthed, dies. And they deliver the news to David:
"He [David] answered, "While the child was still alive, I fasted and wept. I thought, 'Who knows? The LORD may be gracious to me and let the child live.' But now that he is dead, why should I fast? Can I bring him back again? I will go to him, but he will not return to me."

This above all should really be our attitude towards people in our lives who have not accepted Christ yet. For me personally, that would be my grandfather, whose faith and decision on whether or not he really believes in Jesus Christ wavers every day. The last I heard from my parents was that he had declared himself an unbeliever again (and yet he still goes to church with my parents). While my grandfather is alive, should I not also follow David's example fasting and weeping, pleading with the Lord for Him to save my grandfather? Especially now, since as my grandfather gets older in years, I keep on receiving news from home that his mental status is deteriorating (Alzheimer's). I was convicted of my lack of prayer and petition for him and for others in my life who are not saved (e.g. my dad's entire family). Should I not plead with God as much as possible while my grandfather is alive? For when my grandfather dies, I can do nothing more. I will go to him (as I get closer towards the end of my life and to death) but he will not return to me (time cannot go backwards and death cannot be reversed). And who knows, the Lord may be gracious to me and my family.