St. Theodore the Studite: Everyone who sins is a slave of sin...
Indeed it is written, Everyone who sins is a slave of sin; but the slave does not abide in the house for ever. The son abides for ever. Since then we too have been granted to have been called sons according to grace, we remain in the house for ever, if we hold firm the beginning of our undertaking to the end.
St. Theodore the Studite
