I think the only way to keep evil out is by letting God in.
If evil is affecting your life...let God in! Evil will flee.
1 Corinthians 6:19
Or do you not know that your body is a temple of the Holy Spirit who is in you, whom you have from God, and that you are not your own?
If evil is affecting your city...let God in! Evil will be pushed out.
You are the light of the world. A city set on a hill cannot be hidden;
If evil is affecting you country...let God in! Evil will be nullified.
For what great nation is there that has a god so near to it as is the Lord our God whenever we call on Him?
1 John 1:5
This is the message we have heard from Him and announce to you, that God is Light, and in Him there is no darkness at all.
Think on these things.