Mark the Ascetic - On the Spiritual Law 117-120

117. Reaping unwillingly the wickedness we deliberately sow, we should marvel at God's justice.
118. Because an interval of time elapses between sowing and reaping, we begin to think there will be no requital.
119. When you sin, blame your thought, not your action. For had your intellect not run ahead, your body would not have followed.
120. The secret sinner is worse than those who do evil openly; and so he receives a worse punishment.