Mysterion in the New Testament has shed its pagan association with secret initiation rites and instead denotes a divine plan that was long concealed but has now been disclosed through God's redemptive action in Christ. Paul is the term's great theologian: the 'mystery of the gospel' he was appointed to proclaim (Eph 6:19) is that Gentiles are fellow heirs with Israel in one body (Eph 3:3-6), a secret 'hidden for ages in God' (Eph 3:9; Col 1:26-27). He speaks of the 'mystery of Christ' (Col 4:3), the 'great mystery' of marriage as an image of Christ and the church (Eph 5:32), and the eschatological mystery that 'we shall not all sleep, but we shall all be changed' (1 Cor 15:51). Jesus introduces the term in the Synoptics as 'the mystery of the kingdom of God' given to the disciples but withheld from outsiders (Matt 13:11; Mark 4:11; Luke 8:10). Revelation applies it to the seven stars and seven churches (Rev 1:20), Babylon the great (Rev 17:5, 7), and the consummation of God's purpose (Rev 10:7). Spanish 'misterio,' French 'mystere,' and German 'Geheimnis' all preserve the revelatory weight.