1 John 3:20 For if our heart condemns us, God is greater than our heart, and knows all things. If you do anything you believe is not right, you are sinning. James 4:17 Remember, it is sin to know what you ought to do and then not do it.
Romans 8:2 For the law of the Spirit of life in Christ Jesus has made me free from the law of sin and death.
No matter how much you can speak to a person about Christ, if the spirit is not involved, you are waisting your time. I used to enjoy criticizing Christian until one day God decided himself to end it. John 8:9 Then those who heard it, being convicted by their conscience, went out one by one, beginning with the oldest even to the last. And Jesus was left alone, and the woman standing in the midst.
Sin is spiritual therefore requires spiritual intervention. Sometimes you hear people commenting about spiritual things when they are not spiritual themselves and act like they know it all. Time will come when Jesus will take control of their lives, one just hope it’s not too late for some. John 8:12 Then Jesus spoke to them again, saying, “I am the light of the world. He who follows Me shall not walk in darkness, but have the light of life.”
Saul thought he’s got everything under control not knowing that he will hit a forced stop in his life. When all you think you knew becomes a lie. Acts 9:3-4 As he journeyed he came near Damascus, and suddenly a light shone around him from heaven. Then he fell to the ground, and heard a voice saying to him, “Saul, Saul, why are you persecuting Me?”
The fact that I don’t drink or smoke does not make me a better judge. All judgement is reserved for Jesus who died on the cross. Romans 2:1 You may think you can condemn such people, but you are just as bad, and you have no excuse! When you say they are wicked and should be punished, you are condemning yourself, for you who judge others do these very same things.
I might not smoke or drink but have a heart full of unforgiveness, hatred and jealousy. All sins can be forgiven except the one that leads to death. There are drunkerds who will receive salvation and come and overtake us in this walk.
Matthew 12:32 NLT
 Anyone who speaks against the Son of Man can be forgiven, but anyone who speaks against the Holy Spirit will never be forgiven, either in this world or in the world to come.
1 John 5:16-17 If anyone sees his brother sinning a sin which does not lead to death, he will ask, and He will give him life for those who commit sin not leading to death. There is sin leading to death. I do not say that he should pray about that. All unrighteousness is sin, and there is sin not leading to death.
There are sins that God can forgive you for and that which lead to death. Matthew 12:31-32 “Therefore I say to you, every sin and blasphemy will be forgiven men, but the blasphemy against the Spirit will not be forgiven men. Anyone who speaks a word against the Son of Man, it will be forgiven him; but whoever speaks against the Holy Spirit, it will not be forgiven him, either in this age or in the age to come.
We have written off people because of what we see them doing. A person can commit a sin and immediately go to God in repentance. King David is one of our perfect example. He had a repentant heart. People were skeptical when they had to receive Paul because of his past life style.
1 Timothy 1:13 even though I used to blaspheme the name of Christ. In my insolence, I persecuted his people. But God had mercy on me because I did it in ignorance and unbelief.