First, IMHO, a great deal of emphasis is placed on Sanctfication in the writtings of the Reformers and others of the reformed faith. I can think of several works, The Practical Works of Richard Baxter (4 vols), Godliness Through Discipline (Adams), Renewing Your Mind in a Mindless Age (Boice), The Religious Affections (Edwards), Practical Religion (Ryle), Aspects of Holiness (Ryle), Holiness (Ryle), The Mark of a Christian (Schaffer), True Spirituality (Schaffer), Sanctification (Spurgeon) and several others that deal in some part with the topic. (Though I may not agree with everything that is written in everyone of the books above I do see some value in each)

Next, The reason why so much emphasis is placed on justification is that several denominations attempt to get the cart before the proverbial horse and attempt to get the works before the justification.

Man is NOT saved by works! No Exceptions! Man is saved UNTO good works (Eph 2:8-10), and again, No Exceptions. Where people get mixed up is they think they are justified, saved....or otherwise by their works--they are not! True godly works are a natural outflow from a regenerated person who is walking in the spirit and not fulfilling the lusts of the flesh.

In part, Sanctification is growth that takes place by grace that enables one to more fully do the works that God has ALREADY saved them to do.

Charles Hodge said:

Sanctification in the Westminster Catechism is said to be "the work of God’s free grace, whereby we are renewed in the whole man after the image of God, and are enabled more and more to die unto sin and live unto righteousness."

Agreeably to this definition, justification differs from sanctification, (1.) In that the former is a transient act, the latter a progressive work. (2.) Justification is a forensic act, God acting as judge, declaring justice satisfied so far as the believing sinner is concerned, whereas sanctification is an effect due to the divine efficiency. (3.) Justification changes, or declares to be changed, the relation of the sinner to the justice of God; sanctification involves a change of character. (4.) The former, therefore, is objective, the latter subjective. (5.) The former is founded on what Christ has done for us; the latter is the effect of what He does in us. (6.) Justification is complete and the same in all, while sanctification is progressive, and is more complete in some than in others.

Sanctification is declared to be a work of God’s free grace. Two things are included in this. First, that the power or influence by which it is carried on is supernatural. Secondly, that granting this influence to any sinner, to one sinner rather than another, and to one more than to another, is a matter of favour. No one has personally, or in himself, on the ground of anything he has done, the right to claim this divine influence as a just recompense, or as a matter of justice.

Hodge, Charles, Systematic Theology, (Oak Harbor, WA: Logos Research Systems, Inc.) 1997.

Reformed and Always Reforming,