I would like to make a suggestion here...and I really hope I'm not offending anyone, but I have noticed some of the quotes are from theologians who may or may not be saints. I find the words of elders who have been blessed by God with charisms and heroic virtue; such as the Elder Porphyrios and Paisios, as being more edifying to ones soul.
Here is an excerpt from the book by the Elder Porphyrios: Wounded by Love.
"Man has such powers that he can transmit good or evil to his environment. These matters are very delicate. Great care is needed. We need to see everything in a positive frame of mind. We mustn’t think anything evil about others. Even a simple glance or a sigh influences those around us. And even the slightest anger or indignation does harm. We need to have goodness and love in our soul and to transmit these things.
We need to be careful not to harbour any resentment against those who harm us, but rather to pray for them with love. Whatever any of our fellow men does, we should never think evil of him. We need always to have thoughts of love and always to think good of others. Look at Saint Stephen the first martyr. He prayed, Lord, do not hold this sin against them. We need to do the same.
When we speak evil about someone, an evil power proceeds from within us and is transmitted to the other person, just as the voice is transmitted on sound waves, and in point of fact the other person suffers evil. It is something like the bewitchment of the evil eye, when someone has evil thoughts about others. This occurs through our own indignation.
We transmit our evil in a mystical way. It is not God who provokes evil, but rather people’s wickedness. God does not punish
, but our own evil disposition is transmitted to the soul of the other in a mysterious way and does evil. Christ never wishes evil. On the contrary, He commands, Bless those who curse you... http://orthodoxinfo.com/praxis/elderporphyrios_dispositions.aspx