being justified as a gift by His grace through the redemption which is in Christ Jesus;
In Christ we have justification given to us as a gift. You don’t earn a gift you simply receive it. Justified means you have been “Declared Righteous” (made right with God). This was all made possible through the redeeming work of Jesus our Lord and Savior. Redemption refers to an exchange, or a release, provided by the payment of a ransom.
For example in a movie where someone is taken captive by evil men, they may require a ransom to be given for the release of the one they have taken captive. Through the fall of Adam, sin has taken mankind captive and held them in bondage to it’s destructive ways. Jesus came as our payment, our ransom to deliver us from sin and it’s destructive ways. We could not free ourselves, but He had the power to free us.
Jesus died and went into hell paying the ransom for our deliverance. For all who receive Him, they can now be free from the power of sin and darkness. He did not die so that we could claim to be like Him and yet choose to live with sin. He died so that we in accepting His payment for us could choose to walk away from sin, being liberated from that old sin nature, and now live for and with God, because we have been given right standing with Him. Choose to walk in the liberty you have been given by walking with God, not with the world from whom Jesus paid the price to liberate you from.