The Rights of Muslims in Islam

1. Overlook the faults of a Muslim.
2. When he cries, have mercy on him.
3. Conceal his shortcomings.
4. Accept his excuses.
5. Remove his difficulties.
6. Always be good to him.
7. Gaining his love is an accomplishment.
8. Fulfil his promises.
9. When he falls ill, visit him.
10. When he passes away, make dua for him.
11. Accept his invitation.
12. Accept his gifts.
13. When he shows kindness to you, show kindness to him in return.
14. Be grateful for his favours upon you.
15. Help and assist him at the time of need.
16. Safeguard his family and children.
17. Assist him in his work.
18. Listen to his advice.
19. Accept his intercession.
20. Do not make him feel despondent over his ambitions.
21. When he sneezes and says "Alhamdulillah", say "Yarhamukallah" in reply.
22. If you find a lost item of his, return it to him.
23. Reply to his greeting.
24. When you converse with him, speak with humility and in a good manner.
25. Be kind and friendly to him.
26. When he takes an oath with regard to you, confident that you will fulfil it, then you must fulfil it. (For example, Zayd takes an oath that Amr never goes to the bazaar and he is confident that Amr will fulfil this oath of his, then Amr must ensure that he does not act contrary to it.)
27. If anyone oppresses him, go to his assistance. If he oppresses someone, prevent him.
28. Be friendly to him and do not antagonize him.
29. Do not disgrace him.
30. Whatever you like for yourself, like for him as well.
31. When you meet him, make salam to him. If a man shakes the hand of a man, and a woman shakes the hand of a woman, it will be even better.
32. If a quarrel takes place between the two of you, do not cut-off speaking to him for more than three days.
33. Do not have evil thoughts of him.
34. Do not be jealous of him nor should you hate him.
35. Direct him towards good deeds and stop him from evil deeds.
36. Have mercy on the young and respect the elderly.
37. If there is a conflict between two Muslims, try and reconcile them.
38. Do not speak ill of him.
39. Do not cause him any loss; neither in his wealth nor in his honour.
40. If he is sitting, do not make him get up and take his place.

Reference: Rights In Islam Written By Maulana Ashraf Ali Thanvi Rahmatullah Alaihi