St. Athanasius, in the Catena Aurea, is recorded as saying, "For us, perhaps, these things were written; for as not to confer grace on Himself was He made man and circumcised in the flesh, but to make us Gods through grace, and that we might be circumcised, in the Spirit, so for our sake is He presented to the Lord, that we also might learn to present ourselves to the Lord." I think that makes perfect sense. Jesus became man in order that He may present man, being circumcised in the Spirit, through grace, to the Father through Himself.
Now, St. Athanasius had said, "...that we also might learn to present ourselves to the Lord." This is true. There will come the day that we will have to present ourselves to the Lord. Not only will we have to present ourselves to the Lord, we must "look" like Jesus Christ. How will we be able to do this? Although it is true that we must learn to present ourselves to the Lord, we have Hope. Jesus did not present Himself to the Father; His Mother, the Virgin Mary (with Joseph) presented Him. It was His Mother that presented Him at the temple. The Virgin Mary is also our Mother because Jesus made her our Mother at the cross. The Catholic Church, Christ's Body, is also our Mother. Mary and the Catholic Church will present us to the Lord. Not only will the Virgin Mary and the Catholic Church present us, but the Catholic Church is the Body of Christ; therefore, Christ Himself will sanctify us and present us.
The Virgin Mary really had no earthly reason for purification for she conceived not by man but by the Holy Spirit. Nevertheless, she obeyed the Law because she was human and had need to be purified by her Son, as is the Catholic Church, His Body. Although she was without sin, she still needed a Savior, as she stated in the Magnificat. It was by reason of her Son that she was without sin; hence, she was purified by Him. The same applies to the Catholic Church. Jesus was obedient to His parents, as we are to the Catholic Church--or should be and try to be.
Oh, Lord, so wonderful, magnificent, and holy, we are so sinful; nevertheless, look not upon our sins but look upon the faith of Your Church, of which we are members, and keep us. Glory be to the Father and to the Son and to the Holy Spirit; as it was in the beginning, is now, and ever shall be, world without end. Amen.