I find Dallas Willard’s quote on this to be very simple and encouraging.
“Grace is not opposed to effort, it is opposed to earning. Earning is an attitude. Effort is an action.” - Dallas Willard The Great Omission
“Grace is not opposed to effort, it is opposed to earning. Earning is an attitude. Effort is an action.” - Dallas Willard The Great Omission
That is when a Protestant might say, "Well it is clear and perfect in it's [Protestant / sola fide] meaning. And that the billions of other Christians, try as extremely hard as they may, with millions spending immense portions of their live trying to ascertain what God meant for them, have been led astray for all of time."