Make every effort to live in peace with everyone and to be holy; without holiness no one will see the Lord (Hebrews 12:14 NIV).
It is difficult to interpret “holiness” above as anything but practical, actual holiness lived out day to day. Yes, when we first accept Christ, the Lord’s holiness is imputed to us by grace through faith. But the writer of Hebrews urges us to “make every effort…to be holy”. “Effort” on our part is indeed involved. It is very risky to depend simply on Christ’s imputed righteousness to enter the kingdom of God—after a lifetime of not having made any effort at living a holy life as commanded in Hebrews 12:14 above.
This “effort” is not to be confused with what we call “good works” based on vain human effort. Rather, this effort is with the help of the indwelling Holy Spirit who graciously teaches us, enabling us to put to death the works of our flesh and to live a holy life pleasing to God.
Titus 2:11 For the grace of God has appeared that offers salvation to all people. 12 It teaches us to say “No” to ungodliness and worldly passions, and to live self-controlled, upright and godly lives in this present age, 13 while we wait for the blessed hope—the appearing of the glory of our great God and Savior, Jesus Christ, 14 who gave himself for us to redeem us from all wickedness and to purify for himself a people that are his very own, eager to do what is good.
The grace of God therefore is much more than simply a covering for our sins through the blood of the Lamb. Rather God’s grace teaches and enables us to say “No” to sin and to live self-controlled, upright and godly lives in this life. Grace not only saves us, it purifies us and transforms us to be like our Lord Jesus and to do good works.
Ephesians 2:8 For it is by grace you have been saved, through faith—and this is not from yourselves, it is the gift of God— 9 not by works, so that no one can boast. 10 For we are God’s handiwork, created in Christ Jesus to do good works, which God prepared in advance for us to do.