Romans 3:21-31 the righteousness of God in Salvation

Romans 3:21-31 - How can salvation be free if God is Holy and punishes sin? and if Salvation really is free, what reason do we even have for obeying any of His commandments? These are questions asked by modern and ancient followers of Christ. Here is what the Apostle Paul had to say about it - Salvation may be free, but that doesn't mean it was cheap.

if Righteousness and obedience is so important to God that Christ shed His blood for it - it should be important to us too.