WHY it matters//
What we believe about Jesus determines what we believe about ourselves. When we become a Christian our old sinful identity is put to death. We are then “born again” through God’s Spirit to live a new life empowered by the life of Christ. Paul writes that we are literally hidden in Christ (Col 3:3) and members of his body, the church (Col 1:18). Everything we need comes from remaining in Christ.

WHAT it's talking about//
The Apostle Paul wrote this letter from prison to the church at Colosse in Asia Minor around 60AD. This church was not started by Paul himself, but by his convert, Epaphras. This young gentile church was being threatened by false teachers imposing religious rules, so called mysteries, and false ideas about Christ. Paul corrects these false teachings (and others) and helps to establish the believers in the truth of their salvation in Christ.

Colossians 2:8-12 NLT

8 Don’t let anyone capture you with empty philosophies and high-sounding nonsense that come from human thinking and from the spiritual powers of this world, rather than from Christ. 
9 For in Christ lives all the fullness of God in a human body. 
10 So you also are complete through your union with Christ, who is the head over every ruler and authority.
11 When you came to Christ, you were “circumcised,” but not by a physical procedure. Christ performed a spiritual circumcision—the cutting away of your sinful nature. 
12 For you were buried with Christ when you were baptized. And with him you were raised to new life because you trusted the mighty power of God, who raised Christ from the dead.