How much time in a day do we spend on memories? Dwelling on our memories can catapult a person into a mire of sadness and halt all forward progress we might look forward to in a day. Sometimes focusing on certain memories can trigger a downward spiral into depression which can lead to even more problems.
But the right kinds of memories can encourage, lift up, and increase faith. Many times I have heard it said, "The mind is the battlefield". I believe it. We must choose carefully what we allow to linger in our minds.
Scripture often tells us to remember the things God has done for us. When I meditate on times in the past when God has clearly spoken to me, or definitely acted on my behalf, my faith is easily strengthened and actually grows. In this way, I am responsible for the condition of my faith (even though I know that it is a gift from God). It becomes easier to detect the whispers of doubt that come from my spiritual enemies, and reject them as lies.
If you have Parkinson's Disease, you are limited in what you can do, and you are not as physically active as you once were. In my case, this leads to an ever more active mind, so I must take charge of my mind and be careful not to allow the wrong kinds of thoughts in. Proverbs 23:7 tells us about man: "For as he thinks within himself, so he is."
Don't let your mind wander without direction. No matter the condition of your body - no matter what you are not able to do - THIS you CAN do: discern whether your thoughts are good or bad and allow only memories that will increase your faith and move you forward.
The choice is yours. Do you want to have a healthy faith?