Simply put, deception involves acting in such a way that leads another person to believe something, that you yourself do not believe to be true (or know to not be true)!
If someone asks you about your day, and you say it was great, but in reality it was awful...is that deception?
If you are crushing on someone and you learn they really like doing a certain activity and to impress them, you say you also love doing that (but never have)...is that deception?
If you change your plans, your dreams, or your personality just to please someone else...is that deception?
People often claim they are not misleading others, but yet they intentionally withhold important information. Honestly, I don't know why we are wired this way. Because the very foundation of "real" love and the core of "genuine" friendship is honesty and grace. This is the foundation that our relationship with Christ is built on. He never sugarcoats anything and in all things, He extends grace. And Truth!
If God is our example, then as Christ Followers, we MUST stop deceiving people (and ourselves!) God actually gave us a rule about this, it's found in Exodus 20...
"You shall not bear false witness against your neighbor." (Vs. 16)
In other words... DO NOT LIE! Some of us wonder why our relationships crumble, I dare say the foundation that is built on deception will be a shaky one.
If you are a deliberate deceiver or if you have been hurt by a deceiver, remember that God always gets the last Word and truth will always be revealed! And that's the honest, to goodness TRUTH!