"Eucharist" refers to the Body and Blood of Jesus Christ confected through the words of consecration at Mass. Today, the word "Eucharist" has come to refer to the reenactment of the Lord's Supper at the altar or the ceremonial table on which the Eucharistic meal is prepared. That same word also refers to the Body and Blood of Jesus, which is reserved or housed in the tabernacles in Catholic Churches around the world. The primary reason for reserving the Eucharist in the tabernacle was to bring it to people as "Viaticum", which refers to the Eucharist as food for the final passage through death to eternal life.
In the Middle Ages, Holy Communion was infrequent and there emerged a deep sense of the Real Presence of Jesus in the reserved Eucharist. Various rituals of adoration became frequent and were given new emphasis with the establishment of the Feast of Corpus Christi in 1264. So we can see three elements associated with the Eucharist: Jesus offers Himself once again to the Father in the Sacrifice of the Mass; he offers Himself as spiritual food to believers for the on-going journey of living the Christian life; He is present to us in the quiet place of adoration and recognition of His Real Presence in the tabernacle. Now let's go back to the original questions. We offer the Body and Blood in the form of bread and wine because Jesus tells us to eat and drink and when possible the opportunity to receive in both forms should be provided.
On the other hand, it is not necessary to receive under the form of bread and wine because the Church down through the ages has always taught that Christ is present, whole and entire, in the form of consecrated bread and also in the form of consecrated wine. This teaching gave rise to the long standing tradition of receiving Holy Communion under the form of consecrated bread only. However, the Catechism of the Catholic Church notes in paragraph 1390 "the sign of communion is more complete when given under both kinds, since in that form the sign of the Eucharistic meal appears more clearly." But what is most important is that no matter how you choose to receive Christ in the Eucharist is that you recognize Holy Communion to be an intimate union with Jesus Christ and through Christ to be in union with all the brothers and sisters in faith who also share that intimate union. By the way, your response of "Amen" when the minister says "The Body of Christ" or "The Blood of Christ" is an affirmation of your faith in the Real Presence, a profound act of faith!
At Assumption we have Eucharistic Adoration on the First Friday of the month from 7:30 to 9:30am and on the Fourth Monday of the month from 5:30 to 7:00pm