Is that what your church teaches?The author of Genesis was trying to convey something by writing the ages of people who lived back then.
In Genesis, it is written that before the flood people lived to close to a thousand years, but after the flood they did not live past 120 years.
What was being conveyed is obvious. Men who were evil were made worse by their extended lives, so God shortened the lives of man, most likely by altering the atmosphere after the flood.
Whether you believe it or not is irrelevant, but at least try to understand the point of the author.
Just imagine how much damage a man like Hitler could have done living a thousand years. He half destroyed the world in only about 50 years.