why is God so vain??

i have had people asking me,
'Why is (your) GOD so vain??
Why does He always want people to praise, glorify and honour Him?'

Today i thought John Piper answered it wonderfully succintly well, in his book Desiring God.
'What does it mean to glorify God? It does not mean to make him more glorious. It means to acknowledge his glory, and to value it above all things, and to make it known. It implies heartfelt gratitude (Psalm 50:23). It also implies trust (Romans 4:20).

God created us 'in His image' so that we would image forth His glory in the world. We were made to be prisms refracting the light of God's glory into all of life. Why God should want to give us a share in shining with his glory is a great mystery. Call it grace or mercy or love-it is an unspeakable wonder. Once we were not. Then we existed for the glory of God! Therefore it is the duty of every person to live for the glory of God. 'So, whether you eat or drink or whatever you do, do all for the glory of God' (1 Corinthians 10:31).'

So you see, God is not vain. You are being the vain one when you steal His glory in your life.