The word 'Ibaadah' in the Quran is usually translated as 'Worship' or 'Service' by
most translations. But when I did root analysis of this word, I came to realize the richness of this word which the transalations do not even come close in covering.The root of this word 'Abd' literally meant a plant which the camels ate. It produced more milk in them but induced severe thirst as well when eaten.From this root usage and other like it, the root actually means something which is difficult and painful in the beginning but beneficial in the longrun.Another example - The root was used as a verb for beating someone in order to discipline him. Now the beating is uncomfortable, but it did lead to that person becoming disciplined in the end. Again the same meaning. What that means is that Obedience to Allah is difficult and painful in the beginning but is beneficial in the long run and ultimately leads to comfort and ease.
I explain this more in depth here in my article :
https://www.quranicanalysis.com/fatihah-4/. I think you may benefit from it.