In the words of Ezekiel we find, in one promise, this twofold blessing God bestows through His Spirit very strikingly set forth. The first is, ‘I will put within you a new spirit,’ that is, man’s own spirit is to be renewed and quickened by the work of God’s Spirit. When this has been done, then there is the second blessing, ‘I will put my Spirit within you,’ to dwell in that new spirit, where God is to dwell, He must have a habitation. With Adam He had to create a body before He could breathe the spirit of life into him. In Israel the tabernacle and the temple had to be built and completed before God could come down and take possession. And just so a new heart is given, and a new spirit put within us, as the indispensable condition of God’s own Spirit being given to dwell within us. The difference is the same we find in David’s prayer. First, ‘Create in me a clean heart, O God! And renew a right spirit within me.’ Then, ‘Take not Thy Holy Spirit from me.’ Or what is indicated in the words, ‘That which is born of the spirit is spirit;’ there is the Divine Spirit begetting, and the new spirit begotten by Him. So the two are also distinguished, ‘God’s Spirit bears witness with our spirits that we are the children of God! Our spirit is the renewed regenerate spirit; dwelling in this, and yet to be distinguished from it, is God’s Holy Spirit, witnessing in, with, and through it.’ 

The Spirit of Christ - Andrew Murray