I found a very helpful statement from Desiring God Ministries (DGM hereafter) on justification and sanctification.
John Piper (whose teaching ministry DGM is) has been accused of heterodoxy, and sometimes even heresy. However, I believe that those who are accusing him of that do not fully understand his position.
Read sections 9 and 10 of DGM's statement. Many people have problems with 10.3 particularly. However, when we consider a full-orbed perspective and the various passages of Holy Scripture, we may be able to see where DGM is coming from.
I encourage you to read the Scriptures listed at the statement itself by going to this link: www.desiringgod.org/media/pdf/affirmation_of_faith.pdf
I think the statement does a good job of considering the full counsel of Scripture, which speaks of how we are justified by faith alone, and how yet we must strive to persevere for final or consummate salvation.
(Some are uncomfortable with the terminology of "final salvation," but when we consider that "salvation" is a broad term in Scripture which includes the whole package of justification, sanctification, and glorification, this should not be too problematic.)
May the Lord continue to aid our understanding of His Word, and may He be pleased to cause us to persevere in the faith once for all delivered unto the saints!