Jesus is talking in Luke 17 about being ready for the Lord’s coming at any time. He may come at any time. They were eating and drinking in the days of Lot, but suddenly fire came from heaven, and Lot went out (Luke 17:28-29). This is a picture of the Rapture. The judgment fell.
But in that moment, the one who is on the housetop should not have to go down because his attachment is to his property on earth, because his goods are there. One who is in the field should not have to turn back and say, “Hey, Lord, I’m sorry I didn’t settle matters with my wife. Can you hold on? Don’t come yet.” Everything must be settled! Your attachments should not be to your property. You should not have to go back from your office or field to settle matters with your wife.
And then He said, “Think of Lot’s wife.” She turned back because of her wonderful garden, her fancy clothes and all the wonderful things she had in her house that were left behind. The Lord is saying if you are attached to the things of earth, you will not be ready for His coming. If you have to go down to the house to get your goods and the Lord says,"Come" and you say, “No, no my goods are down there" or "I have to go back from my field to my house for something," remember Lot’s wife! You should not have to look back for anything.
We must live in a constant state of readiness with our faces set for the Kingdom of God. If the Lord says at the trumpet, “Come!” say, “Lord, I’m ready. I don’t have to go back and look for anything.” Everything should be settled, every sin confessed, everyone forgiven, and you have asked forgiveness from everyone you hurt. You should have no attachments to anything on this earth. You may be a millionaire—there is nothing wrong with being a millionaire if you have earned that money honestly, if you love Jesus more than that million and say, “Lord, my attachment is not to that, but to you and to you alone." This is what I understand to be the meaning of this warning in Luke in relation to the Lord’s coming.
I might also add that it is possible for a person to enter into the New Covenant and go back from it. Hebrews 3:14—"We become partakers of Christ," a very important verse. Hebrews 3:12 says, "take care my dear brethren" and "that one of you can fall away from the living God." You can have an evil unbelieving heart even after coming into the New Covenant because we can be hardened through the deceitfulness of sin (Hebrews 3:13) in a single day. It takes only 24 hours to be hardened through the deceitfulness of sin. It doesn’t take 5 years, it takes only one day. And he says (Hebrews 3:14) you will become a partaker of Christ IF you hold on to that assurance you had from the beginning firm until the end. Then you are a partaker of Christ. So there, Lot's wife is a warning—you came out and then you looked back. Don’t look back.