The nature of sin
Is something a sin if it is thought about, or is it only a sin if a person actually goes through the process of committing the sin?
When we gather together for worship and confess our sins, we often use these words: “Holy and merciful Father, I confess that I am by nature sinful and that I have disobeyed you in my thoughts, words, and actions.” With those words, we speak biblical truths.
We, like all people, are conceived and born with a sinful nature (Psalm 51:5; John 3:6; Ephesians 2:3). That sinful nature produces all kinds of sinful thoughts, words and actions (Mark 7:21-22; Galatians 5:19-21).
The transgression of God’s will is not limited to words or actions. The Bible points to the thoughts and desires of our heart as the origin of sinful words and actions (James 1:14-15). God makes it clear that sinful thoughts are as wrong in his sight as sinful actions (Matthew 5:28; 1 John 3:15).
The wonderful news of the gospel is that Jesus Christ was our perfect substitute in life. He never harbored any evil thoughts. He never uttered sinful words or committed sinful actions. His life was in complete conformity with the will of his Father. More than that, Jesus then was our innocent substitute in death. On the cross, he paid for all our sins—including our sinful thoughts.
In gratitude for the gift of forgiveness, we seek to live for God (Romans 12:1). That includes striving to control our thoughts and think only those things that are pleasing to God (Philippians 4:8).