Prayer with a definite aim that is consciously and intentionally directed to God, toward His End by His method. Usually when we begin to pray in this way, we are not always conscious of God's full intent, but through God's processing we become more aware of His Purpose in an ever increasing way.
In every season, at every opportunity, praying in the Spirit that which is the right measure of prayer to being forth God's Purpose in relation to time and place and age; hence, praying in union with the Spirit of God at the right time (a definite time or a fixed season) will be the right measure of prayer needed to bring about God's purpose.
"With" denotes the means or instrumentality of action, the effective instrument of activity, which in this case is All Prayer.
All Prayer is the whole of devoted prayer ordained by God to bring about His Eternal Purpose - all of prayer, the entirety of prayer - all the prayers dispensated throughout the ages to be prayed through willing vessels in cooperation with the Spirit - all prayers devoted to God and His Full Purpose.
Supplication in the Spirit - Supplication which identifies itself with the sins as well as the needs of God's people - Supplication like Daniel's when he prayed:
"We do not present our supplications before Thee for our righteousnesses, but for Thy Great Mercies. O Lord, Hear ... Forgive ... and Do ,..." (Daniel 9:18, 19).
In The Spirit
Through God's dealings [it is God's merciful grace that He combines the chastening with the using]; thus, through God's dealings, our human spirit is progressively and increasingly becoming more in union with the Holy Spirit and strengthened by the Holy Spirit, as He, the Holy Spirit, utters through us that which is according to the Will of God: -
"For we know not what we should pray for as we ought: but the Spirit Himself maketh intercession ... for the saints according to the Will of God" (Romans 8:26, 27).
(continued with # 10)