Working through Galatians 4:21-31 — which Paul calls the most difficult passage in the letter — this message unfolds the Old Testament account of Hagar and Sarah, Ishmael and Isaac, as Paul's illustration of the difference between law and grace. Legalism, a misuse of God's law, is exposed as a seductive but enslaving counterfeit that robs believers of the freedom Christ purchased on the cross, while the gospel of grace produces true Christian freedom: the liberty to look to Jesus alone for direction, approval, and accountability. Tracing Paul's argument, the sermon shows that freedom in Christ begins with God's grace, requires a supernatural new birth, brings joy to God and to his people, provokes opposition from those still enslaved to legalism, and finally lays hold of God's promise and inherits his eternal, imperishable inheritance kept in heaven. The call is to stand firm in that freedom, to drive legalism out of our own hearts and the church, and to rest as children of the free woman through faith in Jesus.

Continuing in Galatians (4:8-20), this message confronts legalism — a misuse of God's good law — as one of the dominant poisons in Bible-teaching churches, and holds up joy in Christ as its antidote. Astonished that the Galatians would turn back from grace to the 'weak and worthless' principles of the law so soon after coming to faith, Paul reminds them of the gospel's riches. The sermon traces four causes for rejoicing that strike at a legalistic spirit: rejoicing in knowing God personally rather than merely knowing about Him; rejoicing in being known and loved first by God; rejoicing in the ministry of God's true servants, even when their truth-telling stings; and rejoicing in God's goal that Christ Himself be formed in us by the Spirit. The call is to watch for legalism's many faces, fix our eyes on Jesus as our righteousness, peace, and joy, and 'pray for the wind' of the Spirit rather than striving in the flesh.