Be Perfect as Your Father in Heaven Is Perfect

The word teleosis is mature, perfect in the sense that a father is not being a reasonable dad if he expects his five year old to have calculus. So we strive to please the father and allow him to basically fill us. For Aquinas, mercy is God's power. It's the omnipotent power of his love in action. And so if God loves us more than we love ourselves, as a father loves a child more than the child can even realize, then he's going to perfect us how through mercy. And that's how we become holy.