Human effort will give a certain amount of energy, but it is unsustainable in spiritual matters. Remember the “stony ground” and the “thorny ground” in the parable of the sower? No Fruit! Only “Holy Spirit power” is consistently sustainable.
God the Holy Spirit led Paul from the Roman province of Asia across the sea to Macedonia, where God the Holy Spirit led him to various cities for short times until leading him to remain in the strategically placed commercial city of Corinth for long-term evangelism.
Because of Adam’s sin in the garden, man’s default mode was set to “Sinner under the condemnation of God.” Many people attempt to reset their default mode, but only the Creator can reset man’s default mode when an individual surrenders to the Lord Jesus Christ.