To express that our Father seeks "true worshipers" who "must worship in spirit and truth" (John 4:23-24). Worship is the cultivation of our hearts and minds so that we give Him proper reverence and praise.
To inquire first not what we think of God, but what He thinks of us, and how we adore and serve and cherish Him. We do not sit in judgment on God, but God judges us and rightly calls us to account in all we do.
To glorify God and magnify Christ as the purpose for the church. Worship is what we will keep doing, now and into eternity, after all other vital tasks of the church in and for this present age are concluded.

Worship as summarized at Magdalen Chapel in Edinburgh, Scotland:
The submission of all our nature to God
The quickening of conscience by His holiness
The nourishment of the mind with His truth
The purifying of the imagination by His Beauty
The opening of the heart to His love
The surrender of the will to His purpose