not lagging in diligence, fervent in spirit, serving the Lord Romans 12:11 (NKJV)
Our life and service in the Lord is likened to a walk. When one has just started, they’re all excited and built up but after some time and distance it’s common to be tired and worn out. Concerning out Christian walk and service the Scripture is admonishing us not to burn out but stay fervent or fired up in spirit. Stay fired up by concentrating on and spending more time and fellowship with the Lord (Isaiah 40:28-31). Instead of being concerned with what hasn’t been done and taken up by what must be done, focus on the Lord. He’s the One who fuels and fires us up.