Gumble tells the following story:
I once met a woman called Jean Smith, who was then in her sixties. Sixteen and a half years previously she had an infection that had irrevocably eaten away the retinas and mirrors behind her eyes, and left her blind. As well as having to rely on a guide dog, she was also in a lot of pain. She had attended an Alpha course in her local church in Wales. On the weekend away she experienced the power of the Holy Spirit in a way she never had before. Amazingly, the pain she had suffered for so many years simply stopped. She went to church that evening to give thanks to God. The minister of her church then offered to anoint her with oil to signify this healing that had taken place over the weekend (in accordance with biblical practice). Wiping away the oil, she looked up, and she could see the communion table in front of her. She went home that night and saw her husband for the first time in sixteen and a half years. She could not believe how white his hair had gone!