Yes, God can heal in one instant, by faith you are healed. He is sovereign and HE will heal when and how He wants. We must do the footwork. If we are not setting healthy boundaries, God cannot set them for us, but He can and will slow us down one way or another and physical illness is the quickest fastest way He can stop us. We will get into enough pain to where we have to set a boundary whether we want to or not. Okay so that is my itty bitty human opinion...and something I am learning one day at a time with God's help and guidance and most importantly HIS love!!! Boundary setting is one of the hardest things I have ever had to learn (continuously learning) but it is a must if I am to live out God's plan and will for my life. It is like the oxygen mask of self-care...when you are on the flight you must put on your oxygen mask first before you can help anyone else.
"Another way to discern our distinctive life is from the perspective of discovering our 'sealed orders' from God. Sealed orders, historically, referred to specific written instructions given, for example, to the captain of a ship regarding his destination or mission. They are not to be opened until a specified time or place is reached. It is as if God has given each one of us sealed orders for our lives. He invites us to open them by paying attention to the littler everyday things that give us life...'When I am in touch with the special purpose of my life in carrying out my sealed orders, I have a profound feeling of consolation or rightness and m whole BODY relaxes. I believe the sense of rightness expresses itself physiologically bc the purpose of our life is built into the very cells of our body.'"