What does it mean that the old and new are incompatible?

In his message, the preacher explains that Jesus' parables of new wine and old bottles illustrate the profound incompatibility between the old covenant of law and the new covenant of grace. The old nature, characterized by sin and self-righteousness, cannot coexist with the new life that believers receive through faith in Christ. This new life requires a new creation, which transcends and fulfills the old ways. Therefore, believers are called to embrace their new identity and live according to the Spirit, rejecting legalistic attempts to earn God's favor through works. This teaches Christians that genuine transformation cannot happen through mere external observance of the law but through an internal change initiated by the Holy Spirit.