Unless the Lord builds the house, its builders labor in vain. Unless the Lord watches over the city, the watchmen stand guard in vain. In vain you rise early and stay up late, toiling for food to eat—for he grants sleep to those he loves.
Psalm 127:1-2 NIV
The most important thing is not to do our best to work as hard as we possibly can to achieve the most that we can possibly accomplish towards our objectives. Rather, the most important thing is to align with God and what He is doing. Otherwise we are just wasting energy. He will bring success to that which He desires, and sleep and peace to those He loves.
Trust in the Lord. Seek Him and His face. Inquire of Him and follow where He is working, and enjoy the blessings that result.
Lord, You are good. Your love endures forever, and I thank you that You lavish Your love on me. Lord, help me not to go off in my own direction, working in my own strength on that which I think is important. Rather, show me what You are up to, and allow me to join into the work You are doing. Let it be a blessing for me, and shower me with the peace and the rest that You grant to me because You love me!