There is a crucial distinction between means and ends. Ends are the goals we have set our hearts on, while means represent the habits or disciplines through which we can realistically hope to attain those goals.
The end of exercise is fitness, and the means is training in both cardio and strength. The great goal of the Christian life is to know God, and the means are the spiritual disciplines. We need to be careful that we maintain this distinction, for as Jerry Bridges warns us, we are prone to make the means of grace an end unto themselves. Specifically, he says “We must remember that the methods of spiritual discipline are a means to the end, not the end themselves.”
Instead of understanding the means of grace as the habits through which we come to achieve that great goal of deepening our relationship with God, we can come to see the means of grace as the sum and substance of the Christian life. Instead of pursuing God, we pursue the means, assessing our faith not by our likeness to God, but by the quality or consistency of our reading, prayer, and fellowship. We must always look beyond the means to that great and wonderful and motivating goal of knowing our God.