Answered by Shaykh Faraz Rabbani
1) If someone is overwhelmed with an idea and have made decision before doing istikhara, will there be any chance that istikhara will change the previous decision?
Yes, it is possible.
The proper manners of istikhara (the prayer of seeking guidance) include suspending one’s preferences and consigning one’s affairs to Allah, seeking His guidance towards what is best for one.
[See below for the fiqh of the prayer of guidance.]
The istikhara (guidance) prayer is a gift from Allah to direct our affairs towards success and baraka.
It is also a lesson in developing one’s trust in Allah and one’s sense of need of Allah, to become of those who, “depend on guidance from their Lord. These are the successful.” [Qur’an, 2.5] It is a means to realize that, “ My success is only through Allah.” [Qur’an, 11.88]
This realization, that it is Allah Most High alone who gives and takes, and that nothing in creation moves or is at rest except through the Will and Power of Allah, is the essence of true, living faith.
The Prophet (Allah bless him and give him peace) said, “Say, ‘There is no ability nor power except through Allah,’ (la hawla wa la quwwata illa billah) because it is a treasure of the treasures of the Garden.” [Bukhari, Muslim, Abu Dawud, Tirmidhi, Nasa’i, and Ibn Maja] The scholars say that one who truly realizes the meanings of this is already in the Garden of spiritual meanings, rejoicing in the Pleasure of Allah.
2) If two people do istikhara for the same reason and the one with more knowledge and experience in deen, madhab and taqwa got the +ve answer for that matter while the other one with less knowledge and experience got nothing or no change in the previously made decision about the same matter, what should be done and whose istikhara should be acted upon?
It would depend on the situation. They should discuss the matter, think about the optimum course of action, seek advice if necessary and perhaps (after all this) repeat their istikhara.
3) In the situation mentioned in question no. 2, would it be permissible for the second person who could not receive any answer from the istikhara to do istikhara once more?
It is recommended to repeat the istikhara up to seven times (or even more)