Two things that believers are constantly warned against are (1) legal notions concerning worship and obedience and (2) indifference in worship and obedience. One may evidence itself in a fervent activity in these things, but they are not motivated by the absolute certainty of salvation and final glory strictly from the goodness, grace, and love of God in Christ. One may seek to worship continually and obey constantly, but without that motive of love which comes from knowing that we are justified and permanently members of God's family based solely upon the righteousness of Christ our Substitute and Surety, our worship and obedience are nothing more than the actings of a legal, mercenary spirit. God requires worship and obedience from the spirit of adoption. This is recognized and maintained by His grace as justified sinners worship and obey motivated by the absolute certainty of salvation, eternal blessedness and final glory, based upon the imputed righteousness of Christ alone.
The other will evidence itself in a slothful attitude toward worshipping God publicly in the assembly of the saints, a lazy attitude in prayer to God, and a negligent attitude concerning our character and conduct and how we appear before men. True believers are to seek to be fervent, diligent, and eager to worship, to pray and obey, from the right motive of grace in Christ. We are to strive to bring our character and conduct into conformity to Christ. And although we realize that the natural man cannot recognize the Spirit of Christ, and although we do not want our lives to be nothing more than mere outward show, we do need to appear righteous before men in the sense that we need to live lives which are consistent with the Gospel we profess. We are to be zealous in love, worship, prayer, obedience and good works of every kind, not to obtain or maintain salvation, but as we are eternally saved in Christ, knowing that His righteousness secures for us all of salvation before we make any efforts to obey and serve God.