NOTES for 2 Кор 5:15-21
In practically every one of his letters, Paul in one way or another touches on the question of what the essence and meaning of Christianity are. And Second Corinthians is no exception. Here Paul reminds us again that Christianity is not some new religion or new moral teaching, but a new life, whose newness consists in the fact that it belongs not to us, but to Christ, who came into the world in order to share it with each of us who is willing to receive it. Only in this way can we both share in the Kingdom and be freed from sin.
This new life that enters us through Him is like a blood transfusion in certain serious illnesses: there are cases when the patient's blood has been irreversibly poisoned, so that the only thing left is to replace it with other, fresh blood. And our life, given to us by God, has been poisoned by sin so deeply that the only way to keep us from dying is to replace that former life with another, new one, free from sin.
Is that not why Christian life is so joyful and so difficult at the same time? Living in the Kingdom is certainly joyful, but then one has to consent to a "transfusion of life," and therefore to renounce once and for all something so familiar, habitual, and in many ways comfortable, despite all its problems. But this is renunciation for the sake of the Kingdom. And each person makes his own choice.