Providential happenings may serve to remind us, more or less vividly, that God is as work (cf. Acts 14:17), but their link, if any, with His saving purposes cannot be known until He Himself informs us of it. No event is self-interpreting at this level. The Exodus, for instance, was only one of many tribal migrations that history knows (cf. Amos 9:7); Calvary was only one of many Roman executions. Whoever could have guessed the unique saving significance of these events, had not God Himself spoken to tell us?
J.I. Packer, God Has Spoken, Revelation and the Bible, Hodder and Stoughton Ltd, 1979, pg. 76