Is the Tribulation foretold in Holy Scripture upon us?

The Bible does not say specifically when the Great Tribulation would start, however we do we have signs of "the last days" in the Gospels; however, they also show us how to survive the Great Tribulation if we are willing to learn about God's requirements for us to survive. In John it states "...only the Father knows, not even the Son of God nor the angels in heaven." Also John states: "...it will come as a thief in the night." If man knew when this time period would begin, they may begin to devote their lives to God only for survival, instead out of love for his Kingdom.