What does it mean to stand fast in faith?

To stand fast in faith as described in Galatians 5:1 entails being steadfast and immovable in the belief that Christ has accomplished all that is necessary for our salvation. It opposes the notion of earning righteousness through works of the law or succumbing to the influence of 'Judaizers' who promote a false gospel of legalism. This is a call to abide in the freedom provided by Christ, to trust in His finished work, and to live out our faith through love and the guidance of the Holy Spirit.