'Number' in the Bible

Little children, it is the last hour; and as you were given word that the Antichrist would come, so now a number of Antichrists have come to you; and by this we are certain that it is the last hour.

They went out from us [seeming at first to be Christians], but they were not really of us [because they were not truly born again and spiritually transformed]; for if they had been of us, they would have remained with us; but they went out [teaching false doctrine], so that it would be clearly shown that none of them are of us.

My loved ones, do not put your faith in every spirit, but put them to the test, to see if they are from God: because a great number of false prophets have gone out into the world.