TRANSFORMATION, An inward renewal and reshaping of the mind through which a Christian’s inner person is changed into the likeness of Christ.
Ezekiel 11:19 (NCV)
19 I will give them a desire to respect me completely, and I will put inside them a new way of thinking. I will take out the stubborn heart of stone from their bodies, and I will give them an obedient heart of flesh. 
Spiritual Transformation, This promise is applicable to all of us who yields ourselves to God for renewing and transformation.
The nature that needs transformation;
It is our hardness, that sin nature that keeps us focused on ourselves and satisfying our needs with no concern of others. It’s that stubborn heart, which Divine grace undertakes and renews and softens. It’s that stubborn heart that makes us insensible to mercy, righteousness, law and even the Gospel. In this nature we resist all that is Godly.
The power that effects the transformation;
Due to our powerlessness in renewing ourselves, even with our limited influence in change, we discover that we need a total renewal. Only God the Almighty is capable of such. He needs no counselor, no helper, he has unlimited resources at His disposal and He does as He pleases to accomplish what is needed.
In this scripture it is not known as to His means of that renewal, however in the Christian disposition, transformation is provided by the indwelling Holy Spirit, given at the day of Pentecost, made available by the death, burial and resurrection of Jesus Christ. We partake of that power and transformation by faith and believing as we hear the Word
The effects and evidences of this transformation.
Newness of spirit supersedes the old disposition to disobey and rebel. 
Unity of heart comes to supersede the division and opposition which prevail when God’s authority is rejected and God’s Word is despised.
The heart of flesh is sensitiveness. God provides a nature by His grace that produces gratitude, faithfulness, and consecration, (the desire to set ourselves apart). Our heart starts desiring what is pleasing to God and dreading what is unpleasing to Him. We begin within our heart to do all that is in obedience and lovely to Him. In fact that heart of flesh that only He can provide is the BEST gift we could receive.
Paul told the Roman believers, “Be transformed by the renewing of your minds” (Rom 12:2).
As one’s Christian life progresses, the person should gradually notice that his or her thought life is being changed from Christlessness to Christlikeness.
Transformation does not happen overnight—regeneration is instantaneous, but transformation is not.
Christians are transformed to Christ’s image gradually as they spend time beholding him in intimate fellowship.
Eventually, they will begin to mirror the one they behold. Paul said, “We all with unveiled face, mirroring the glory of the Lord, are being transformed into the same image, from one degree of glory to another, even as from the Lord who is the Spirit” (2 Cor. 3:18—from the Greek).
This does not come from conscious imitation but from spiritual communion with the Lord.
The result will be beyond our expectations.
The apostle John said it well: “We can’t even imagine what we will be like when Christ returns. But we do know that when he comes we will be like him, for we will see him as he really is” (1 Jn 3:2, nlt).
God’s power (dynamis) is mentioned often in Paul’s letters. It is a characteristic displayed in many ways, including the evidence throughout creation, the witness of natural revelation: “For since the creation of the world God’s invisible qualities—his eternal power and divine nature—have been clearly seen, being understood from what has been made, so that men are without excuse” (Rom. 1:20). Creation bears testimony to the reality of God’s power and makes people accountable to acknowledge Him properly.
Zuck, Roy B.: A Biblical Theology of the New Testament. electronic ed. Chicago : Moody Press, 1994; Published in electronic form by Logos Research Systems, 1996, S. 249
 The Everyday Bible : New Century Version. Nashville, TN. : Thomas Nelson, Inc., 2005
 Spence-Jones, H. D. M. (Hrsg.): The Pulpit Commentary: Ezekiel Vol. I. Bellingham, WA : Logos Research Systems, Inc., 2004, S. 201
nlt New Living Translation