Luke 9:11

But when the crowds learned of it they followed Him; and He welcomed them and He began talking to them about the kingdom of God, and healing those who needed to be healed.

We can have faith but still doubt in our hearts. If we are struggling to use our authority over our sickness, then we need to renew our minds with what Jesus said about healing. We may need to remind ourselves of the kingdom of God and of Jesus’ healing of all who are sick. We need to imagine ourselves healed and remind the body of what Jesus has already done.