Life is hard and requires effort. That idea is exciting to me when I realize what it enables. Growth happens in trials through a refiner's fire, and intense effort can mean intense growth.
God's opportunity is man's extremity. -John Flavel
When I served a mission I found myself pushed to some physical and mental limits. It required a lot of effort but resulted in unbelievable growth in myself. I left my mission more confident, strong, mature, and optimistic.
The Gospel of Jesus Christ requires effort as well, it's not enough to say I believe if I don't follow it up with action.