Dear Luis:
Demons cannot read our minds, but they can influence our imaginations.
They can influence our imaginations in the same ways that I can influence your imagination -- by subtle suggestion, temptation, exploitation of your weaknesses, creating situations, bring people into your acquaintance, etc.
The difference is the demons have the ability to be far more talented and economic than I can be in influencing you.
No matter what the influence, however, it is our free will choice to indulge in the imaginations or tempting situations.
The other major way that demons can get a grip on us to influence us is when we invite then to influence us.
We invite demons to influence us every time we sin, every time we disobey the Church, every time we are careless and do not take into account the near occasion of sin, everything we think the old demonic song, "it's justa....", such as "it is justa a game, what can it harm", "it is justa movie, or TV show, or musical piece.
As we are coming up to Halloween, we will begin to hear the demonic choir singing "It's justa fun holiday" with a fierceness of a hurricane.
The best way to avoid the influence of the devil is to live the high road, not the low road, of the Christ-Life, avoiding even the near occasion of sin, and accepting St. Paul's admonition to pursue and to think upon that which is excellent, not that which is merely good, but that which is excellent.
God Bless,
Bro. Ignatius Mary