I believe in sacrifice especially when loved is involved...I do everything I can to help those I love even if it costs me or I have to displease myself
We must sacrifice ourselves for the benefit of people because by prioritizing the interests of others we are taught not to have selfish attitudes, and to be generous people towards others. Just as our prophet Muhammad Muhammad SAW did, who educates his wives to put others first, give food to others even though sometimes the food does not leave them. Likewise when the Messenger of Allah asked the Companions to be reconciled so that there was no sense of misery and selfishness in themselves by giving alms all the possessions they had.
Subhanallah is very beautiful behavior to put others first that is done by our prophet, which is to overtake the interests of others even though you have to sacrifice for that person. We should have to imitate to always be able to imitate the example of the example and what was done by our prophet, because prioritizing others can make us able to be trained to not be selfish in making a decision so that we always put others first before ourselves. However, what happens most of the time is not to prioritize other people than themselves, but now people are more selfish than people around them.
What if the nature of putting others first is done in worship? It may be that around us often happens, for example, it happens when you will pray in a mosque. Mr. x had arrived early and got the first shaf, but later there was Mr. Z who came and did not find the first shaf. Then Mr. X invited Mr. Y to take his position, just because the simr. Y was his boss. Now this is also one example of people who have the character of giving priority to other people compared to themselves, both in matters of worship. Because of the nature of this is what the apostle of Allah likes and loves, which prioritizes the interests of others compared to himself even though he must sacrifice himself in order to put others first before himself.
Off course not if you believe in Karma then you should drop the idea of self interest because karma always pays back, when you help someone just think that you are doing a good job, it is in Gods hand to rewards you or not. In today's world most of us help other with some self interest which is I think not bad because being selfish is not bad but not good for long time.
Helping other with self interest is depends upon person to person, If I am help someone who is able to do a favor for me then it good to have self-interest., but if I am helping some financially who is unable to pay me back or cannot do a favor for me then idea of self interest is bad. sometime in life you just do the thing without thinking much more about profit and loss.