So let no one judge you in food or in drink, or regarding a festival or a new moon or sabbaths, 17 which are a shadow of things to come, but the substance is of Christ (Colossians 2:16-17).
In these two verses we get some insight into the “philosophy” threatening the faith of the Colossian believers in Christ (2:8). In part, the philosophy was meant to deceive the Christians in Colossae into adopting practices prescribed in the Old Testament law. The concern was not simply that people would observe dietary laws and special days, but that they might see those observances as essential to salvation. Paul’s message is that Christians are complete in Christ, and need only to trust in Him to be pleasing to God (2:9-10). In fact, these laws were a shadow of things to come while the substance is of Christ.
As it was back then, today there are religious philosophies about how to inherit eternal life. These philosophies can all be boiled down to a works salvation. That is people can be saved, have eternal life through doing good works. But the Bible teaches something very different. People are saved by faith alone in Christ Who died for their sins and rose again! For by grace you have been saved through faith, and that not of yourselves; it is the gift of God, 9 not of works, lest anyone should boast (Ephesians 2:8).