I have developed a friendship with a family, formerly in the pastorate, but due to the wife's Alzheimer's disease, they retired and make it the best way they can. My friend asked me, "Larry, do you know the hardest thing about this?" I assured him that I did not, though I ventured a few sensible guesses. He told me, "Doing the things that are required physically are painful for certain, dealing with the fact she is with me physically, but inwardly off somewhere is hard. I feel so emotionally abandoned because she cannot love me, I am just here."
Concerning physical intimacy, he had a grip on that, but the spiritual interaction of older couples was gone; she did not recognize him, having actually dialed the police assuming he was a burglar. In spite of the rigorous ordeal Alzheimer's placed on his wife, he said, "Larry I love her more deeply than ever."
I had no idea what to say, I listened and prayed. I thought of a verse Paul gave to Timothy and it touched him deeply when I applied the truth that he was imitating Christ in his deep love for his wife; 2 Timothy 2:13 "If we believe not, yet he abideth faithful: he cannot deny himself." The point being that as God's children He loves us when we are bound up some way.