Wahb ibn Munabbih said that Aadam (as) cried for 300 years after eating from the tree and never looked up after being sent down to earth.
The Prophets were forgiven by Allah, yet they weren’t complacent! We should be in the state of regret even after the sin, even if it’s many years later.
The least that can be said is that it’s recommended to repent and feel regret for sins which a person did in the past and for which one has already repented for.
If you find out that someone has offended you, either behind your back or to your face, go to that person and say, calling him nice names, I apologise for whatever bad I’ve done to you, please forgive me.
The easy option is to get upset and argue back. Rather, know that this is due to your own sins so apologise to the person and repent.
Shaykh ’Uthaymeen, may Allaah have mercy on him, said:
“When they see a person sinning, many brothers hate the sin and this is something correct, but they [also] hate the sinner, and then they deal with him harshly as someone who hates him would, like someone who wants to take revenge on him, and this is a huge mistake.
You must cure the sinner as a gentle doctor who treats a wound in order for it to heal does, he doesn’t treat the wound in order for it to get worse, so he treats this person with gentleness and a desire for good for him and out of mercy for him … this is how the scholars who nurture are, they look at the creation with a view to reform, not to seek revenge and out of hatred—I hate the sin which this person does, but this person is a believer so he is my brother, even if he fornicated and stole, he is still my brother, the believers are but brothers.”
[Majmoo’ Fataawaa wa Rasaa’il Fadilatish-Shaikh Muhammad ibn Saalih al-’Uthaimeen, vol. 27, pp. 311-312]
Some of the people of the past would say, we don’t tell you to leave the dunya but rather leave sins.
This means that you can live comfortably; you don’t have to be poor but ensure that you are staying away from sins.
A man came to Muarraq al Ijlee and said, I can’t get up at night to pray or fast during the day. Muarraq al Ijlee responded, if you can’t do good, then don’t do bad.
This means that if you see your Emaan affected and going down, then don’t do more haraam, rather maintain what you have.
If one is lying about another then he will be sinful. On top of that he is causing fitnah and too much talk hardens the heart. As does too much joking.
A joker is never taken seriously especially in matters of religion.
And if he is making jokes of sins, which the other has done and repented from, he will most likely be afflicted by it.
Remember that if a blessing has been taken away, and you find you can’t do something you used to do easily, it’s because of your sins.