What are the conditions for a prayer to be answered, and does it affect destiny if it includes a request to marry a specific woman?

Supplication is part of Allah's decree and a means to receiving a response. Therefore, one should not be preoccupied with divine decree and the whispers of Satan, but rather work with the means, supplicate, and seek refuge in Allah. One must beware lest apathy lead to abandoning obligatory duties; instead, one should strive diligently to adhere to the Sunnah (definition).