What happened to the first church?

Many on here insist that Catholics are not Christians and are not the first church. If they are not what happened to the church? Did it disappear from the face of the Earth for 1500 years? Was it hidden somewhere? If so how was it a light on the hill like Christians are supposed to be? Where are the writing from the church during the time when the only visible church was the Catholic (and Orthodox) church? Did God allow the church and Christians to die out for nearly 1500 years? Where was the church? Evidence and not just conjecture would be nice.