Multiplied calls to prayer are found throughout Scripture, and many men and women in the pages of the Bible are also found travailing in prayer to God. We are to pray without ceasing, to pray everywhere, and to pray in spirit and truth. We are called to pray for kings and rulers, and also to pray for the saints who are the Body of Christ (all those that are born from above, as children of God). Christ Himself was discovered throughout His earthly life in earnest prayer to His Heavenly Father, and we would do well to take heed of the reason for prayer.
Prayer expresses a need that we are unable to satisfy. It is an acknowledgment that we live in total dependence upon the Lord. The essence of all prayer is an admission of utter helplessness combined with absolute confidence in God to supply all our needs according to His great riches in His great glory. When we live in an attitude of prayer, when we pray without ceasing, we are simply maintaining the ongoing and constant attitude of simple, child-like trust and helpless dependence upon the Father.
To pray in the Spirit is only possible when we are living in unbroken fellowship with the Father, for a life that is living, walking, and praying in spirit and truth is one is submitted to His leading and guidance, for the one that lives in helpless submission and dependent upon the Holy Spirit, is the one that truly prays in the spirit.
Source: https://dailyverse.knowing-jesus.com/ephesians-6-18