Matthew 24:40-41, “Then shall two be in the field; the one shall be taken, and the other left.” 
Matthew 25:1-13, Jesus said only half of Christians will be Raptured…the other half will remain on the earth to go through the Great Tribulation.
“WHAT? Not all Christians will be Raptured? I don't...

...believe it!!!” Well, Jesus said in the Bible multiple times that not all Christians are going up. If for some reason you do not go up in the Rapture, what follows is a brief outline on how to overcome Satan during the Great Tribulation. 

            Revelation 12:11 tells us how to overcome our enemy:  “And they overcame him by the blood of the Lamb, and by the word of their testimony; and they loved not their lives unto the death.”  These are essential for overcoming Satan on earth after the Rapture:

            “By the blood of the Lamb”— This means more than being saved. It means that we need to be dedicated to the sacrificial love of God, being true to the Gospel, caring about others, and even loving our enemies. It means having the same love for Christ and for others, which Christ has for us. Christians will be hated and a huge number turned over to authorities even some by family members, to be martyred.

            “By the word of their testimony” — A report given of who we really are, and what God has truly done in our lives. There is a power God gives to us that only comes if we are obeying Him, following Him, and trusting in Him with every fiber of our beings.

            “Loved not their lives unto the death” — Many Christians not Raptured will be martyred, or killed for their faith. Others will face jail, or isolation and abandonment. God will provide strength for every situation. There will be a serious price for missing the Rapture and having to be a light for Christ during the Great Tribulation. But thanks be to God for His great mercy, there will eventually be great heavenly reward as well. The believers that overcome during the Great Tribulation, have the job of repopulating the world for 1000 years, while Satan is cast into Hell.