I like to do these arguments where I give the other side their argument, just to show them their argument still doesn't hold any water. I'm saying this without having watched the video yet. But I'm pretty sure I know where you're going with it.
For instance, the story above, I will say to the person, ok, let's just say it was God's will for them to be born that way. That still doesn't change anything, BECAUSE THEY WERE STILL HEALED. IT WAS STILL THE WILL OF GOD FOR THEM TO BE HEALED. So in order for you to do the will of God, regardless of why they were born that way, YOU NEED TO HEAL THEM. :)
And I can use that same argument for any story in the Bible where they say what happened was God's will. Job, etc. it works for them all. Most focus on Job's suffering and leave out the fact HE WAS TOTALLY DELIVERED, HEALED, AND TWICE AS BLESSED BEFORE IT HAPPENED. So I tell them if you consider yourself a Job, you need to be dancing and singing and praising God because deliverance is on the way. Same as the story above, if you believe it's God's will for you to be sick and basing it on that story, you need to be dancing and sining and praising God because it basically
guarantees your healing.