Footnote 12

Mysteries. This term, in the Bible's original Greek language, generally refers to something that God has revealed that could only be known by revelation. However, the way Paul uses the term is more nuanced than that. For Paul it also means knowledge previously hidden and, when that secret is expounded it appears quite innovative, fresh, new (perhaps even controversial) – not something that has been previously announced in Scripture (the OT for Paul). Thus, for Paul, the partial hardening of Israel is a mystery (Rom 11:25), the Apostles were stewards of the mysteries of God (1Cor 4:1), the Gospel is a mystery (Romans 16:25-26, Eph 6:19) and the Union of Christ and the Church is a mystery (Eph 5:32). That the saints will be transformed at the Parousia is a mystery (1Cor 15:51). Paul calls Christ (in whom are hidden all the treasures of wisdom and knowledge) the mystery of God (Col 2:2; 4:3). All these and the words spoken in tongues might be mysteries but they are not mystical in the sense of being some weird manifestation of an ineffable “spirit”. The Holy Spirit is the source and the content is wonderful. So: a mystery – yes, mystical – no.