Guess What Am I?

You can clip me, hold me, stick me, throw me, stab with me, and play with me.  I come in many colors of the spectrum and I can express myself in many colors and in many mediums too. 

I can be fat and bulky or slender and slim, but can still be gripped with thumb, fingers, and hands.  Some like to even use their toes or their mouth. It all depends on your preference on how I am held and used.

Some strangle me, some lightly grip me, but all use me to express themselves.  They list with me, draw with me, and scrawl and play with me.  I help them express everything from boredom, fear, pain, love, and happiness to all that in which is in between and beyond.  I am there to help express it all.

I have helped others go to war and others to bring peace.  I help give words of comfort.  I also give words of pain.  With my tip with in your grip, you guide me to what I tell.   I am a just tool for all.

Finally, you can buy me, sell me, borrow me, steal me, and accidentally take me.  You curse and stress when you need me or lose me.

What am I?