2 Corinthians 7

Paul begins the chapter with a implication or conclusion of the call of God to come out from the world and be separate unto God and that he would be our Father and that we would be his sons and daughters.  The chapter begins with "Since we have these promises" which links back to chapter 6 and then tells us what we must then do in response: "purify ourselves from everything that contaminates body and spirit perfecting holiness out of reverence for God."
This call has serious implications about what kind of movies we watch and own, what kind of music we listen to, what kind of activites we engage in, what kind of conversations we have.  It reaches to both physical (contaminates body) and spiritual (and spirit).
The purity is not so much about having clean clothes and a clean house, though that can be included, it is more speaking to a moral impurity or mixture.  The term "purify" relates to removing mixture.  We cannot be mixed in our actions or words.  This is similar to what James says about our speech that it should not both "praise our Lord and Father" and "curse men" (James 3:9-12) and then that "friendship with the world is hatred toward God" (James 4:4).  There cannot exist a mixture and think that it is pleasing to God.
We cannot worship God on Sundays and at Bible Study and then at other times during the week be hating others, or speaking evil of others, or watching movies with sexual immorality, or getting drunk etc.
Paul calls for a radical holiness.  In the last chapter we saw the statement "touch no unclean thing".  This ties back to some Old Testament concepts such as things devoted to destruction (Joshua 6:18-7:26).  Items such as those used in witchcraft or false religions as items of worship or practice, or items that a person has sinned with, these are physical items that should be destroyed or gotten rid of.

It should be noted that ultimately we cannot perfect ourselves and if we set about to perfect ourselves, we will ultimately fail, just like the pharisees.  We need to recognize our weakness and call out to God to help us, to change us and set us free.  We need to work diligently, but it will fail if we work in our own strength, because then we will just become proud of our accomplishments, as opposed to humbling ourselves, recognizing our sinfulness and weakness, and crying out to God to rescue and change us.  On the other hand, there are certain physical steps we can take, as Paul points out above, that when we know the good we ought to do, we need to do it.

Paul then begins a section where he describes being very happy about a message that he received from Titus about the church in Corinth.  He was worried about them since his previous letter where he had to correct them sharply, but now he sees that his letter, though it hurt for a while "your sorrow led to your repentance" (v 9).  He then goes into a discussion about "godly sorrow" vs "worldly sorrow" (v 10).  This is an important concept to know about as well.  When we sin, and we will all sin (1 John 1:8), we need to know what to do and how to resolve and handle it.  1 John 1:9 says that we need to confess our sin and that God will cleanse us of all unrighteousness.  Here Paul says that "godly sorrow leads to repentance" (v 10) and that is because God, by his Holy Spirit, convicts us of sin (John 14) but doesn't condemn (John 3:17).  In practical terms, when we feel guilty about sin, it should lead us to repent and turn from the sin.  If so, that is "godly sorrow".  The devil on the otherhand wants to condemn us - make us so discouraged, weighed down, feel like we are a failure and can never do right, that God will never use us, can never use us etc.  All those feelings are condemnation which lead to death which is "worldly sorrow" (v 10).  We need to say "no" to the condemnation, because that is not from God, but say "yes" to conviction that leads us to repent and turn.  We need to show "earnestness, eagerness to clear yourselves, what indignation, what alarm, what longing, what concern, what readiness to see justice done." (v 11).

This kind of repentance causes joy in the heart of God as is brought Paul joy and it brings us joy as well as we find freedom and forgiveness from God.

Let us strive to perfect 'holiness out of reverence for God" and learn how to repent, confess our sins and keep running the race in Christ Jesus.  He is faithful to pick us up when we humble ourselves (James 4:10) and change us into his image.