When Considering Sanctification...

and the attendent aspects such as obedience from the heart... consider this crucial element found in the Westminster Confession of Faith, but not in the chapter on Sanctification. Who cannot relate and say, "Amen?"

5. The most wise, righteous, and gracious God doth oftentimes leave, for a season, his own children to manifold temptations, and the corruption of their own hearts, to chastise them for their former sins, or to discover unto them the hidden strength of corruption and deceitfulness of their hearts, that they may be humbled; and, to raise them to a more close and constant dependence for their support upon himself, and to make them more watchful against all future occasions of sin, and for sundry other just and holy ends.

-Westminster Confession of Faith, Chapter 5 - Of Providence

Yet another reason we must not separate the justification we have through faith in Christ from the sanctification we have in him (1Cor. 1:30).