Assalaamu alayku. While trying to move my laptop, I dropped it and my father heard the noise. However, I told him that it was something else (the charger); also, when one of my sibling opened the door to check what was that noise, I tried to conceal it from her. I lied to my father and my sibling out of fear because they would yell at me, and my sibling might even have taken the laptop from me because it belongs to her. So my question, as I constantly use this laptop for my studies, is: will the things in which I benefit from the laptop be haram for me? I mean, it is like somebody who lies about a product while trying to sell it, would his money be halal? And is that example applicable to my issue?

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah and that Muhammad is His slave and Messenger.

Lying is one of the greatest sins and acts of disobedience. A man continues to lie until he is written with Allaah as a liar – we seek refuge in Allaah from that. 'Abdullaah ibn Mas’ood narrated that the Prophet said, “You should always tell the truth, for the truth leads to piety and piety leads to Paradise. A man tells the truth and persists in speaking the truth till he is written before Allaah as a truthful person. Beware of lying, for lying leads to vice (wickedness, evil-doing), and vice leads to Hellfire, and a man persists in telling lies till he is written before Allaah, as a liar.” [Al-Bukhari and Muslim]

Therefore, you have to turn to Allaah in sincere repentance and commit yourself to telling the truth and stay away from lying.

You should also be careful not to violate the rights of others, even if they are the closest people to you, as the Prophet said, “Verily, your blood, your wealth and your honor are sacred (to one another).” [Al-Bukhari and Muslim]

Therefore, it is not permissible for you to use your sister's laptop without her permission, especially if you know that she forbids you from doing that. Also, if she authorized you to use it in the past and you know that if you inform her about what really happened, she would prevent you from using it, then, apparently, you have to tell her because her permission, in this case, no longer exists.

In any case, if you took her laptop without her permission and you used it to study and you passed your exams or got a degree, then studying while using her laptop does not have any effect on your success or your work in the future; however, along with repentance, you should ask her to forgive you for transgressing her right without her permission or consent.

Finally, what you have mentioned about selling goods while lying and so on does not apply to your case [it is a totally different matter].

Allaah knows best.