Envy not greatness: for thou mak'st thereby
Thy self the worse, and so the distance greater.
Be not thine own worm: yet such jealousy,
As hurts not others, but may make thee better,
   Is a good spur. Correct thy passions' spite;
   Then may the beasts draw thee to happy light.

From George Herbert, "The Church-Porch" in The Complete English Works, 16

Envy has spite in it. It’s a form of contempt. It not only wants someone’s position or possessions, but doesn’t want them to have that position or those possessions out of spite. The best way to detect envy is when our emotional reactions are backwards: We hear someone’s good news and we don’t want to rejoice–or we hear someone’s unlucky news and we rejoice. George Herbert says this type of envy is sinking us lower, making us rot (being our own worm).

However, sometimes we have a milder form of jealousy that is closer to admiration–and if removed of competitive spite, can actually spur us on and make us better. How do we remove the spite? By being diligent about rejoicing with those who are rejoicing and mourning with those who are mourning. Get those competitive “beasts” properly reigned in humility and care for others, and then we may “spur one another on to love and good deeds.”