“GOD ALWAYS WAS THE HEALER. He is the healer still, and will ever remain the Healer. Healing is for YOU. Jesus healed, “all that came to Him.” He never turned any one away. He never said, “It is not God’s will to heal you,” or that it was better for the individual to remain sick, or that they were being perfected in character through the sickness. He healed them ALL. Thereby demonstrating FOREVER God’s unchangeable will concerning sickness.”
― John G. Lake, The Collected Works of John G. Lake

People make promises and break them. We have become conditioned to that and almost come to expect it and, because of that, deep down we are not sure if God will keep His promises.

But it states in the scriptures, ‘I am the Lord, I change not’. People like John Lake knew that and that was one of the secrets of their ministry. He knew that once God declared Himself to be the healer, He was the healer for all time. Once He healed one person the precedent was set for all to be healed.
The only thing that stands between us and our healing is trust in the fact that God will do exactly what He said He will do!