Legalism= trying to earn by your own efforts what God only gives for free.
The content of Paul's message was that a person is saved through faith in Jesus Christ, not through keeping the Jewish religious laws.
The issue is the condition of your heart.
To be “crucified with Christ”
1. I live through Christ. (20a)
When we change the way we think, we change the way we live. (Romans 12:2)
2. I Live by faith. (20b)
Your “moving forward” is a step of faith.
Many times, we don't want to move forward on the strength of our faith, but on the strength of a feeling.
3. I live in grace. (21)
Many Christians want their relationship with God to be based on payment for services rendered, not undeserved mercy.