It has been said that those who live by the sword will die by the sword. This is true. The manner in which we treat others will also be used against us.
Those who dig a pit to entrap others will inevitably fall into a pit themselves. Those who attempt to use surprise against someone else will eventually encounter a rude awakening themselves. This might not happen immediately. But it will occur in due time.
How much better to be someone who always deals with people with honesty and grace! You are blessed when you bless those around you and treat them righteously. Not only can you generally expect to receive better treatment in return, but you also have the intense satisfaction in knowing that you are treating others as Christ would.