God will heal all illness and disease - but not in this world. You say, “But it seems like this one is a dark tunnel that ends only in death.” That’s not so bad! This life, in this fallen world, is by design difficult (but not entirely without consolations and joy) and temporary.
God allows every man trials as He chooses, some very heavy ones, and through every one He is able to work good, blessings
exceeding the suffering that comes with the trial. For our part, we must trust Him with the trial, in and through the trial, believing that He is good and the worker of good, always.
Persons who struggle with same-sex attraction, in other words, can be sure that if they remain faithful to the universal call to chastity - to holiness - to celibacy or to sexual purity according to
His design for marriage - but if they remain faithful, He will faithfully bless them and reward them in His eternal happiness, in glory.
And they, for their part, will be working with their faithfulness,
with Christ, having their own personal part in His Cross of salvation.
Rev 21:2 And I saw the holy city, new Jerusalem, coming down out of heaven from God, prepared as a bride adorned for her husband;
Rev 21:3 and I heard a loud voice from the throne saying, “Behold, the dwelling of God is with men. He will dwell with them, and they shall be his people, and God himself will be with them;
Rev 21:4 he will wipe away every tear from their eyes, and death shall be no more, neither shall there be mourning nor crying nor pain any more, for the former things have passed away.”