The Word of God is the basis of everything we do in worship (announcements, welcome, songs, prayer, preaching, etc.). Why? Because God works through his Word. He created through his Word (Genesis 1); He sustains his creation through the Word of his power (Hebrews 1: 3); He came to this world as the Word (John 1: 1); He saves us by the power of his word (Romans 1:16).
Preaching is the primary form of the Word in our worship because this is the model Jesus and his disciples left us (Luke 4:43, Romans 10: 14-15) and because we are commanded to preach the Word until Christ returns. (2 Timothy 4: 1-2) And because true worship is based on the Word, when we come together as a church we want to read the Bible, sing the Bible, pray the Bible, preach the Bible, and see the Bible (at Baptism and Holy Communion).