It is a fanatical notion that we interfere with the Holy Spirit if we make any preparation for prayer. The theological deficit in that assumption is that the Holy Spirit would not have us reason or use foresight or imagination or fit language. It assumes incorrectly that the only part of us that the Spirit wishes to work through is emotive impulsivity and spontaneous feeling-flow. It assumes incorrectly that the Holy Spirit does not also work through discipline, reason, reflection, and organization.
Thomas C. Oden, Pastoral Theology: Essentials of Ministry
extemporaneous, holy-spirit, worship