Sometimes we lament about this, thinking that God could do a much better job by Himself. We are so clumsy and slow at times. Yet, this is how God operates, regardless of our questions. He wants us involved and to be active participants. God wills our involvement in the process of sanctification not for us to earn merits or to gain special acceptance with him, but that the marvels of His grace in our renewed personalities may become apparent as we work and act and stand before God as responsible agents.
Sanctification is progressive.
Someone known to have fits of anger should not expect that because he or she is regenerate, he or she will now be sweet and mild in all circumstances. The temper remains, but now it can and must be controlled. God is there now to assist in the struggle. Instead of fighting a losing battle alone, that person can triumph by the grace of God. Often we wonder why God permits us to struggle so long in the life of sanctification.