Have you ever been convicted? Have you ever had this "sudden realization" that you've been doing things all wrong, and the strong urge to stop what you are doing wrong to make things right?
If you have, then you have experienced "conviction". Conviction can happen at any time. The word "convicted" is related to the word "convict". To convict someone denotes an active participation in causing someone else to become convicted. On another note, a "convict" is someone who has been found guilty of a crime. Therefore, if you are "convicted", then you have been found guilty of some action you know is not right and deserves changing in your life.
The word "convicted", although used liberally in Christian circles, is only used one time in the King James Version of the Holy Bible. It is at the part of the story about the prostitute who was caught in the act of sinning. When they brought her before Jesus in order to try to convict him of blasphemy, or false teaching, Jesus told them, "Let he who is without sin cast the first stone." One by one, from the eldest to the youngest, they walked away. In John 8:9 it says that they were "convicted by their own conscience, and walked away."
What is conscience, then, that it should convict anyone?
I have heard it argued that the conscience is the Holy Spirit convicting you; but, according to the Bible, you can have a good conscience or a bad conscience. In 1 Corinthians 8, Paul seeks to use food that has been offered to idols as a example. As Christians, we know that idols are nothing; therefore, we have no problem eating food offered to them. However, those who were raised in idolatry revere idols as holy. If they see you eating food offered to idols they may be offended. Someone who is offended by you may not want to listen to you when you tell them about Jesus, or what is right or wrong. Paul calls their conscience "weak". Therefore, it is diplomatic form, to say the least, to learn their customs and seek not to offend them in order to keep their minds open to your teaching of the Gospel.
To Titus, (Titus 1:15), Paul writes, "To the pure all things are pure. But to those who are defiled and unbelieving, nothing is pure: but even their mind and conscience are defiled."
In Hebrews 9:14, Paul explains how a person with a defiled conscience gets a clean start to rebuild their conscience to God's glory: Nothing but the blood of Jesus.
When you accept Christ into your life your slate is wiped clean. All of your sins are forgiven. From that moment on, you do your best to keep your heart and mind pointed toward Christ, walking in his precepts and laws. From that day forward, your conscience will convict you when you turn down the wrong paths.