1 Timothy 1:18-19
"Let your conscience be your guide" is a well-known expression, but one that isn't necessarily good advice. That's because your moral compass is only as reliable as the principles with which you program it. If you store up proper biblical instruction and training, it will be dependable to safeguard you through life. But using false ideologies from popular culture to program your conscience will set you up for moral failure.
Our heavenly Father has given each person a conscience as a gift intended to be a tool of the Holy Spirit--our one true Guide. As such, it is designed to protect you from going astray. You can trust it only when the following seven statements are true of you:
1. Jesus Christ is your Savior and Lord.
2. The Bible is the basis for your conduct.
3. You have a strong desire to obey God.
4. You make decisions prayerfully.
5. Your conscience sounds the alarm when you consider a wrong direction in thought or action.
6. You feel guilty when you disobey.
7. You feel compelled to repent of your disobedience.
A trustworthy conscience reacts immediately to disobedience. There is no making excuses and no waffling over whether or not something may have been wrong.
To develop a reliable conscience, read and apply Scripture so God's principles will override any prior bad programming. Then, under the Holy Spirit's guidance, it will sound protective alerts. Don't put faith in your conscience alone, but trust God to make it an effective tool for leading you.