Let’s agree that structure and openness to the Spirit are not contradictory priorities. Paul urged spirituals to be operated “decently and in order” (1 Cor. 14:40). Likewise, planning a service is not inconsistent with being open to the Spirit. God carries out plans he arranged long before the events happen (Isaiah 25:1), so he can certainly give leaders a plan for the service a few days before Sunday morning!
Recognize, too, that the larger the group assembled together and the more defined the ending time for a meeting, the less possible it is for many people to exercise a spiritual gift. Smaller gatherings, without predetermined elements or an “order of worship,” will always be the ideal setting for several people to benefit others through an operation of the Spirit—teachings, revelations, prophecies, words of knowledge, etc. (see 1 Corinthians 14:6, 26).
Still, we want our Sunday services to be led by the Spirit—and to model an ever-eager readiness to respond to his leadings. The best modeling will come from a pastor who stays attentive to promptings to take the service in an unexpected direction. That might involve changing the order of service, setting aside the prepared message or simply taking extra time for ministry to the Lord or to one another. The leader should tell the congregation about the prompting, perhaps even describing what it felt like.
Since the Spirit is distributed among all believers, it’s important to alert the congregation to the work of the Spirit through individuals. Perhaps an exercise will help: during worship, ask people to listen carefully for a scripture the Spirit might place on their heart; later, ask them to share their verse (if they received one) with someone near them during breakout time (or prayer circles).
The big question behind this question is: “How can I be open to the Spirit without surrendering leadership of the services to disruptive verbal outbursts that frighten everyone, including me?” I solved that dilemma with simple protocols for people who thought they had a word for us: “If you have attended for at least six months, and you’re sure I know your first name, tell an usher/leader who will then alert me. If it resonates with my spirit, I’ll bring you to the front to share it with everyone.” Members who had a track record merely needed to get my attention with a gesture, and I would invite them up.