LOOK NOT BEHIND THEE
The Bible teaches us that God ended the Church Age and gave commandment that all who were His people were to come out of the Corporate Church. The Bible also indicates that any who have come out of the church only to since return have violated God's command (law) to not go back:
Matthew 24:16 Then let them which be in Judaea flee into the mountains: 17 Let him which is on the housetop not come down to take any thing out of his house: 18 Neither let him which is in the field return back to take his clothes.
Mark 13:16 And let him that is in the field not turn back again for to take up his garment.
Luke 17:31 In that day, he which shall be upon the housetop, and his stuff in the house, let him not come down to take it away: and he that is in the field, let him likewise not return back.
Genesis 19:17 And it came to pass, when they had brought them forth abroad, that he said , Escape for thy life; look not behind thee, neither stay thou in all the plain; escape to the mountain, lest thou be consumed.
THE PENALTY FOR GOING BACK IS DEATH
The penalty for breaking any part of the law of God is death.
Romans 6: 23 For the wages of sin is death;
James 2:10 For whosoever shall keep the whole law, and yet offend in one point, he is guilty of all.
Therefore we’re not surprised to see that the same penalty for violating God's commandment against returning back to the corporate church is also death. Historically, God gave the commandment to Lot and his family (including his wife) as they fled for their lives out of the city Sodom (a figure of the apostate Corporate Church) to not look behind them. Lot’s wife disobeyed this command and was turned into a pillar of salt, which meant that God killed her for her sin of breaking His law to not look back.
Luke 17:31 In that day, he which shall be upon the housetop, and his stuff in the house, let him not come down to take it away: and he that is in the field, let him likewise not return back.
32 Remember Lot's wife.
Genesis 19:25 And he overthrew those cities, and all the plain, and all the inhabitants of the cities, and that which grew upon the ground.
26 But his wife looked back from behind him, and she became a pillar of salt.
BEHIND CHRIST IS WHERE SATAN IS TO BE FOUND
The masculine pronoun used in the statement "behind him" is a reference to Christ. The Bible tells us exactly what (or who) lies behind Christ:
Luke 4:8 And Jesus answered and said unto him, Get thee behind me, Satan: for it is written, Thou shalt worship the Lord thy God, and him only shalt thou serve.
And,
Matthew 16:23 But he turned, and said unto Peter, Get thee behind me, Satan: thou art an offence unto me: for thou savourest not the things that be of God, but those that be of men.
The area 'behind' Christ is where Satan is to be found. Tragically those that have gone back have turned from serving Christ and have turned back to that area identified with the presence of Satan.