Chapter XXI. Of Christian Liberty and Liberty of Conscience.
1. The liberty which Christ hath purchased for believers under the gospel, consists in their freedom from the guilt of sin, the condemning wrath of God, the rigour and curse of the law, and in their being delivered from this present evil world, bondage to Satan, and dominion of sin, from the evil of afflictions, the fear and sting of death, the victory of the grave, and ever- lasting damnation: as also in their free access to God, and their yielding obedience unto Him, not out of slavish fear, but a child-like love and willing mind.
All which were common also to believers under the law for the substance of them; but under the New Testament the liberty of Christians is further enlarged, in their freedom from the yoke of a ceremonial law, to which the Jewish church was subjected, and in greater boldness of access to the throne of grace, and in fuller communications of the free Spirit of God, than believers under the law did ordinarily partake of.
( Galatians 3:13; Galatians 1:4; Acts 26:18; Romans 8:3; Romans 8:28; 1 Corinthians 15:54-57; 2 Thessalonians 1:10; Romans 8:15; Luke 1:73-75; 1 John 4:18; Galatians 3:9, 14; John 7:38, 39; Hebrews 10:19-21 )
2. God alone is Lord of the conscience, and hath left it free from the doctrines and commandments of men which are in any thing contrary to his word, or not contained in it. So that to believe such doctrines, or obey such commands out of conscience, is to betray true liberty of conscience; and the requiring of an implicit faith, an absolute and blind obedience, is to destroy liberty of conscience and reason also. ( James 4:12; Romans 14:4; Acts 4:19, 29; 1 Corinthians 7:23; Matthew 15:9; Colossians 2:20, 22, 23; 1 Corinthians 3:5; 2 Corinthians 1:24 )
3. They who upon pretence of Christian liberty do practice any sin, or cherish any sinful lust, as they do thereby pervert the main design of the grace of the gospel to their own destruction, so they wholly destroy the end of Christian liberty, which is, that being delivered out of the hands of all our enemies, we might serve the Lord without fear, in holiness and righeousness before Him, all the days of our lives.
( Romans 6:1, 2; Galatians 5:13; 2 Peter 2:18, 21 )
Source: The Reformed Reader