Can God and devil be present at the same in a believer?

Here is what The Bible has to say about God and the Devil.

The Devil came into action at the beginning of humankind, confirmed in Genesis chapter 3; 1 John 5: 19; Revelation 12: 9

When Jesus was confronted by Satan, here is what he told him. Matthew 4: 10 reads. " Jesus said to him: " Go away Satan ! For it is written: " It is Jehovah your God you must worship, and it is him alone you must render sacred service."

So according to the Scriptures above, Satan is someone who is real, and even Jesus had to face his tricks, and so as the whole world today.

James 4: 7 reads. " Therefore, subject yourselves to God, but oppose the Devil, and he will flee from you". Which means that a person can defeat Satan by obeying God rather than the Devil.

Satan and the demons are Jehovah's enemies. They are our enemies too. Read Luke 9: 38-42.

To not invite the demons into our lives, Deuteronomy 18: 10-12 says that we should not employ divination, anyone practicing magic, anyone who looks for omens, a sorcerer, anyone who consults a spirit medium or a fortune-teller, or anyone who inquires of the dead. For whoever does these things is detestable to Jehovah God.

Such practice is quite in use all over the world and is part of mankind's culture. Which confirms that the whole world is lying in the power of Satan, as it is written in 1 John 5: 19, but as James 4: 7 confirms, we can oppose the Devil like Jesus did.