cassianus:

“A man who does not pray is one who is content with his own condition. He wishes to remain as he is and not be changed, renewed or saved. His life unconsciously changes from bad to worse. He recedes spiritually day after day. The ties that bind him to the earth and to the flesh increase without his awareness. His ego remains the source of all his desires and ambitions.As for his relationship with Christ, it remains only superficial and outward. It has no power to change or amend anything. The possibility to even deny Christ at times of danger, temptation, illness, or poverty becomes imminent.So if man does not pray, he can never be changed or renewed, and he who is not changed or renewed can have no genuine or effective relationship with Christ. His worship, however active, is nothing but an outward protrusion or a superficial growth. In the end it breaks off, bearing no fruit.”

~Matthew the Poor

This significantly addresses the question “Why do we pray?” from the personal spiritual perspective. Some of us pray with spontaneous words, some with memorized prayers, some with beads, some with clasped hands, some kneeling, some standing. But all praying.