Ralph Erskine (Christ the People’s Covenant), Sermons 1:161:
Hence we may see what are the motives that now should influence the believer in his obedience. If Christ be the all of the covenant, and that he is loosed from all his former relation to the covenant of works, he is not to obey either from a legal hope of heaven or slavish fear of hell. Not from a legal hope of heaven; for the covenant secures the purchase of that by Christ’s perfect obedience: not from a slavish fear of hell; for the covenant hath secured freedom from that by Christ’s complete satisfaction. The principal motive is the love of Christ constraining; the love of a God in Christ, who is given for a covenant of the people. God deals not with believers now according to the covenant of works, neither ought they to deal with him as if they were under it. They ought to mourn for sin, to repent, to confess, to beg pardon, but not in a legal way, as if they had to do with a wrathful judge, but as having to do with a merciful Father in Christ. They are to yield obedience to the law, not out of a servile fear of hell and wrath, but out of a child-like love and willing mind; so far as the believer acts otherwise, so far he is under a spirit of bondage. Neither ought the believer to act from a dread and fear of his being disinherited. So far as he does so, it is not an act of faith, but of unbelief; for he cannot view this covenant, and yet see himself left at an uncertainty. There is no liableness to a forfeiture of its privileges; Christ is the covenant of the people.