Bringer of blessings, reverser of destiny, remover of adversaries, and the shield of a believer – these are some descriptions of the most powerful weapon of a believer: Du'a (supplication). Perhaps one of the reasons why the significance of Du'a is sometimes underestimated is because it is not obligated upon us. If it were made compulsory, we would look towards it with more seriousness. On examining this issue closely, we will find that it is pointless to compare Du'a with the rest of our obligations, simply because of its unique and private nature. When we supplicate, our heart communicates directly with our Lord with no medium in between, and we allow His mercy and blessings to engulf us from all sides. Hence, Du'a not being an obligation provides no excuse for us to stay away from this blessing.
It can also be argued, "If Allah knows my needs, then what good is it for me to ask Him?" No doubt Allah knows our needs more than we ourselves do, but to make such a claim is evidence to the fact that the purpose and meaning of Du'a has not been properly understood. By invoking Allah through Du'a, our attention and hopes are completely directed towards the Almighty. It is also a confession of our insignificance and helplessness without Him. The Du'a is a means of belittling our ego; therefore the Quran proclaims that to neglect Dua is actually a sign of arrogance! (23:60)
Allah says in the Quran, "Call on Me, I will answer you." (40:60) Does this mean our Du'a will always be accepted? Sure, but not as promptly as we might think. Furthermore, some Du'as may not be accepted at all. Does this make us give up our hopes? No, it must not. Rather, it should arouse our curiosity to look into the rationale behind why our Du'as are not being accepted. Some reasons can be lack of sincerity, doubtfulness in the acceptance of Du'a, asking Allah for something which is not permissible, or simply that Allah does not deem what you ask appropriate for you. Also, Imam Ali (peace be upon him) had said: "He who prays but does not exert effort is like the one who shoots without a bow-string." The biggest reason for non-acceptance of Du'as may just be that!
Although Du'a is a means of fulfilling our desires, but its benefits extend farther. As stated earlier, true supplication weakens our egos and uproots all elements of pride. Hence it becomes a great tool for nurturing our spirituality! In addition, it is highly recommended to supplicate in the manner directed by the Infallibles (peace be upon them). These are the supplications that we find in books such as Mafatih al-Jinan, Sahifa Sajjadiya, and the like. They guide us towards the perfect means of approaching Allah, but also illuminate our imagination and increase our awareness (Marifah) of our Creator. Thus, Du'as are perhaps the best sources of Islamic teachings on spirituality.
Let's not forget that we are never unarmed. Our insignificant selves leave us with no means other than Du'a. As Imam Ali says in Du'a Kumayl: "O You who is readily pleased – forgive one who owns nothing but supplication!"
For detailed information about Du'a and related topics, please refer to the book Oddatol Daee (The Asset of a Supplicant), available online.