God is spirit, and his worshipers must worship in spirit and in truth. (John 4:23)
True worship is born out of the Spirit of God. If worship is not born from the Spirit of God, it cannot, by definition, be worship.
I have seen worship teams who excel in professionalism. Their singing is fantastic, they are beautifully organized with every instrument you can think of being played, including whole orchestras. The worship leaders look great, and they can pitch the style of music at exactly the right level between being lively enough for the young people in church, and yet not being too extreme for the older people in church.
Such professionalism can become dangerous for the church. Man’s desire often leads him to try to attract people into the church, by having good, popular, music being played. The trap is when we put the professionalism and the “show” before the Spirit of God. Holy Spirit worship flows in a way that organized music cannot. To worship in the Spirit means to follow the Spirit, His movements and His direction. That is not to say that we have to be unprofessional or unorganized, rather that we need to be able to follow the direction of the Spirit.
The worship leader’s role is to worship before the throne room of God, and from that point to lead the other musicians and the congregation into His Presence. A worship leader must know the way into God’s presence, and then be able to take others into that place. God spoke to me a few years ago about being able to walk up mountains. I spent, and spend, time every week climbing the hills and mountains of Cheshire and North Wales. I was making sure that I knew the way up those hills better than anyone else, and that I could get up faster than anyone else. Leading worship requires the same type of spiritual training.
A worship leader spends his life seeking and living in the presence of God, so that when it comes time to lead other people there, the way is clear and open.