Prayer when the heart is not involved is just words IMO. God is a Spirit, and to worship Him, we must worship Him in spirit and truth. The Jews Jesus chastised prayed prayers great in words but not with their hearts or in the spirit, right?
Hi Bro... After reading your short post I feel I should point out that your first sentence conflicts with your second sentence. First, you say, "Prayer, when the heart is NOT involved is just words." Next you point out that Jesus chastised prayers that are great in words but NOT done "with their hearts OR spirit." There really is a connection between heart and spirit. The mother of a missing child prays for his return out of a heart and spirit that longs for him continually, day and night. Her prayers for him are heartfelt and in the spirit. IMHO a prayer in the Spirit and in truth must come from the heart.
John 1:18: "No one has seen God at any time. The only begotten Son, who is in the bosom of the Father, He has declared Him."
God carries His Son, Jesus, in His bosom. That's another way of saying that Christ is in the heart of the Father in the same way the missing child is in the heart of his mother. So, when Jesus tells us that we are in Him as He is in the Father...Where are we, really?
The "mystery of Christ in you" is a heart and spirit thing. They can't be separated. "At that day you will know that I am in my Father, and you in Me, and I in you." John 14:20.