8 Although he was the Son, he learned obedience from what he suffered. (Hebrews 5:8 CSB)
Obedience is a trait we must practice and learn throughout our lives. It is not a one and done thing.
At times, our lessons in obedience can be hard, but we often make them so much harder. We fight against what God expects from us and even against our own better judgement.
Why do we do this? Especially when we know better?
The human condition and our fallen state create a potent combination. While our hearts yearn for God, our minds are corrupt and seek most frequently our own desires and pleasure above all else.
Thus, we must fight against our own nature if we desire to know God and follow His plans for our lives. To know those plans we must also seek Gods will through scripture and prayer. Seeking to obey even when we desire our own path, even when obeying is hard.
All of this because even if obeying is hard it is in our own best interest in all things. Because obeying reaps eternal rewards.