Speaking with Hashem is the prime manifestation of emuna (faith in Hashem). Since emuna is one of the “constant mitzvot” that we perform 24 hours a day, then Hashem allows us to personally speak to Him 24 hours a day. Rebbe Nachman teaches (Likutei Moharan II: 84), “Know! that the main connection to Hashem is by way of prayer, for prayer is the gate that leads to Hashem.” The Rambam, in Laws of Prayer, says that prayer is basically speaking to Hashem in one’s own words, conversing with Hashem, expressing gratitude, and asking for all of one’s needs taking nothing for granted.
The obligation of prayer is simply an incentive for us to build a close relationship with Hashem. Our main form of communication to Him is through speech. Personal prayer is a very intimate connection with Hashem, in which we determine the time, place, language, and topics of conversation.
Personal prayer to Hashem is much older than the prescribed prayers we have today, which were instituted as a means to keep our people in exile from forgetting how to pray to Him. Every person, regardless of spiritual level, can connect to Hashem directly through personal prayer.
Based on In Forest Fields: A Unique Guide to Personal Prayer, by Rabbi Shalom Arush