As salaamu alaikum wa rahmatullah,
Bismillahir Rehmaanir Raheem

The purpose of life is to worship Allah subhanahu wa ta'ala, and dua is the crux of worship.

Dua: The weapon of the believer Video: Yasir Qadhi (click on link)

Dua: Goes hand in hand with tawakkul (trust and hope in Allah subhanahu wa ta'ala) Dua is the essence of worship: calling to The One, the Only One who can actually help you and Who actually deserves to be called upon. The One who is As-Samad, The Satisfier of every need; upon Whom everything depends but He depends on no one and nothing. Dua is calling upon the Creator, the Sustainer, the Supreme Answerer. [Calling out to other than Allah is the essence of shirk]

وَقَالَ رَبُّڪُمُ ٱدۡعُونِىٓ أَسۡتَجِبۡ لَكُمۡۚ

"And your Lord says: Pray unto me: and I will hear your prayer" [40:60]

Dua is a very personal form of worship; we call directly The One, our Creator, our Sustain-er, Al-Mujeeb: the Answerer. And when we call upon Him privately, and sincerely, and full of humility; it's a very sincere form of worship.

ٱدۡعُواْ رَبَّكُمۡ تَضَرُّعً۬ا وَخُفۡيَةً‌ۚ

"Call upon your Lord humbly and in secret" [7:55]

Allah subhanahu wa ta'ala is indeed near, He hears our call even when we pray silently. He sees every tear that crawls down our cheek, and hears every whisper that emerges from our lips as we call to Him subhanahu for mercy and help. It is of the etiquettes of dua to pray silently, for Allah subhanahu wa ta'ala is Al-Sami, the All-hearer and He is near.

وَإِذَا سَأَلَكَ عِبَادِى عَنِّى فَإِنِّى قَرِيبٌ‌ۖ أُجِيبُ دَعۡوَةَ ٱلدَّاعِ إِذَا دَعَانِ‌ۖ

"When My servants question thee concerning Me, I am indeed close (to them): I listen to the prayer of every suppliant when he calleth on Me" [2:186]

The dua of a believer is accepted!! SubhanAllah, look at Allah azzawjal's mercy! He subhanahu has provided us with a way out of everything, with a solution to all wants and needs, DUA!! A direct link to the source of all solutions. Truly, all praise is due to Allah subhanahu wa ta'ala.

When we make dua we affirm the Greatness of Allah subhanahu wa ta'ala. We affirm our status of being Allah azzawjal's slaves and being dependent on Him subhanahu for everything.

Dua: The weapon of the believer video: Yasir Qadhi (click link)

May Allah azzawjal grant us the tawfeeq to turn to Him subhanahu in times of ease and in times of hardship in gratitude.

BarakAllahu feekum,
wa'salaamu alaikum wa rahmatullah