"As for God having done it in the past. On the occasion of the flood he used a natural disaster but offered protection for anyone who wanted it in the ark. He had to destroy that world at the time because of the violent and cruel halfbreed giants and their demon fathers." - tornapart
Why not just kill the half-breed giants?
Why use a flood? The Bible records that one angel killed an entire army in their sleep.
Jesus also said that the last days would be just like the days of Noah.
In addition, the modern day Noah's Ark is the Christian Congregation of Jehovah's Witnesses.