Paul wraps up his letter to the Galatians reminding them of what the has already so thoroughly laid out- that our only boasting is in the cross of Jesus Christ.
Saying we are saved by grace alone does not mean there is not a Christian life to which we are called. The key to the Christian life is sowing to the Spirit rather than our flesh.
One extension of being a product of grace is extending grace to others. Here Paul tells us to restore sinners bearing one another’s burdens with gentleness.
The Spirit of a Christ will not lead us in lawlessness. Our flesh has been crucified. We are new creatures who need to think of ourselves in a new light.
God has foreordained the means as well as the end. We struggle to hold these realities in tension, but Scripture is clear that God, the First Cause, has ordered things to come about by second causes.
Paul says those who do the works of the flesh won’t inherit the kingdom of God? Is he now adding a works principle to the gospel? Well, no. He is reminding us that the Spirit is real and is at work in us.