Never stop having doubts. If you ever do, it will be because you’ve stopped moving forward, and at that point, God will step in and pull the rug out from under your feet, because that is His way of controlling His chosen ones, by making sure they always follow their appointed path to the end. If, for any reason, we stop, whether out of complacency, laziness, or out of a mistaken belief that we know enough, He forces us on.