Eph. 6:11 "... stand firm against the schemes of the devil."
2Cor. 2:11 "... for we are not ignorant of his schemes."
About the Devil's Schemes:
1. They can be understood.
2. They rely on deception.
3. They often involve surprise.
4. They may develop gradually.
5. They may get switched rapidly.
6. They produce certain results.