Foster asks "How do we enter into this Prayer of Rest?" We tend to think in terms of being active or passive. We think we need to always be doing something, trying harder or passively praying and waiting. Relational prayer is not like that. Foster says "Resting in God does not mean resignation or idleness." He describes this place of prayer as the "middle voice." We neither take action nor passively receive the action of another. He says "We are involved in the action and participate in its results but do not control or define it." In other words we are full participants in prayer but prayer does not depend on us.
Paul tells us in Romans 8:26-27 that the Spirit helps us in our weakness and intercedes for us in our struggling and halting prayers. If you look closely, you will see the heart of the Gospel right here. We were dead in our sins and unable to find our way back to God. The Father sent His Son to make a way for us. We're still incapable of living righteously, praying correctly, or resting fully in God. But Jesus has sent us a helper. Now the Holy Spirit is actively helping us to pray. He gives us an opportunity to participate in prayer, to enter into the place of prayer and communion with the Father. He also enables us to receive from the Lord, to hear with spiritual ears, to have understanding beyond the natural self. The Holy Spirit gives us the power to do, to obey and live out what we receive from the Lord in prayer. We are in control of what happens to us through this process. God will not force us into fellowship and His Spirit will not go beyond our willing release of control. Rest comes when we learn to trust the work of the Spirit. Then our prayer time will change and we will find the place of rest that we all so desperately need.