Hebrews 6:12

That ye be not slothful, but followers of them who through faith and patience inherit the promises.

To be not slothful is to refuse to become spiritually idle through neglect of duty, through unwilling performance, or through complaining and murmuring. Instead the call is to be followers and imitators of those who inherit the promises, following faithful examples with persevering effort in doing good works. Inheriting the promises comes through faith and patience, where faith is readiness to act on what God has spoken, joined with patient endurance in receiving what He has promised. This requires showing the same diligence to the full assurance of hope unto the end, holding fast to hope rather than growing idle.

God is not unrighteous to forget the work and labor of love shown toward His name in ministering to the saints, but looks upon such faithful work with approval. The diligence required is unselfish, whole-hearted, cheerful service wherever a person is placed and whatever work is given, done with gratitude and joy at being counted worthy to work with Him, and no one need be idle because earnest work is always at hand. God is honored by diligent, fervent service and sustains and helps those who render it, while neglect is exactly marked and those who complain and murmur at every step will receive neither help nor reward. Cherished grace in this course leads to spiritual growth and deeper knowledge of divine things. This faith and patience were illustrated by believers in the seventh month who set aside worldly pleasures and prepared for the expected reward, and by Abraham who obeyed without knowing where he was going and did not withhold his only son.