Eph. 5:18-19 says, "be not drunk with wine, wherein is excess; but be filled with the Spirit; Speaking to yourselves in psalms and hymns and spiritual songs, singing and making melody in your heart to the Lord."
For Paul, this wasn't some theological nicety or quaint spiritual theory. This was something he practiced - it was at the core of his relationship with God. When Paul and Silas were cast into the innermost prison after being beaten with many stripes, the scripture says that everyone in the prison could hear them worship before God shook it with an earthquake. Let faith and hope flourish in Worship!