When I entered counseling back in 2010, my hope was that my same-sex attraction would go away and that I would develop real attractions for women. Like real attractions that I didn't have to constantly talk myself into. After 7 months of counseling neither of those things had happened, and I began to become disillusioned and even depressed. Why wasn't this working like my counselor said it would?
What I came to realize is that heterosexuality isn't the goal - holiness is. I began to understand that my holiness before the Lord is not contingent on the orientation of my sexuality. What matters is that I am fighting sin, trusting the Lord and his promises, and relying on the power of His Spirit.
This realization helped me to see that there are at least two different types of change. One is inevitable, and one is not inevitable.
The change of my orientation from gay to straight is NOT inevitable. God never promises me that he will change my desires. I am reminded of Paul praying three times to the Lord in 2 Corinthians 12 that the thorn in his flesh would be taken away, and God says, "No." God decides which thorns stay and which thorns he will remove, for his glory. I have no guarantee one way or the other.
In fact, I think promising orientation change to someone is not helpful at best, and very harmful at worst. There is no set of steps that will definitively lead to a reversal in attraction, and promising such a thing can lead to depression and even suicide when the change doesn't happen as expected. Furthermore, this type of thinking can make orientation change into an idol, an ultimate goal that must be achieved or all is lost. If my hope rested in my becoming straight, then I would have no ground for hope at all. This type of change is far from inevitable.
However, there is a type of change that IS inevitable. What happens when I dethrone heterosexuality as my ultimate goal and replace it with holiness? What happens when I cling to Jesus, cling to his promises in his word, and fight the fight of faith by the Spirit? I change! Indeed, sanctification is a type of change that is inevitable for all true Christians. And here is the thing: My sanctification here on earth may or may not include a change in my attractions. It doesn't really matter. In conforming me into the image of Christ, God may see fit to leave my orientation unchanged until the day I die. And that might be one of the "thorns" that the He uses to increase my faith and display his power and grace in my life.
Orientation change is never promised, and therefore should be held loosely. However, there is a change that is promised. "And we all, with unveiled face, beholding the glory of the Lord, are being transformed into the same image from one degree of glory to another" (2 Corinthians 3:18).