Imagine that you live in the country in a nice house among beautiful, peaceful surroundings. There are birds singing and a nearby brook running. Moreover, you have no financial worries and no one to bother you. Mostly likely, you would be too happy and content to think any evil thoughts. Now, let's thrust you into the working environment of a big city. You have a stressful job and you work hard, but no one appreciates you. You even have to fight for finding a parking space wherever you go. Besides, the cost of living is high and people do take advantage of you. Very likely, you would hate living there and might even devise ways of hurting your enemies. The point I wish to make is that our environment can greatly affect our behavior. My recommendation is to let God shield us from all evil. To be in union with God is to be immersed in him and have himself surround us completely. Making God your refuge is the way to go.