If Jesus is fully present in both eucharistic species, why did Jesus offer both?
Our blessed Lord could have instituted the Eucharist using bread alone. But he instituted the Eucharist to be a living sign of his Passion.The presence of his saving blood signifies that he not only became flesh but that he gave his life on our behalf. When we see his blood separate from his body on the altar, we recognize that at Mass we are celebrating the fact that he actually died for us. The moment at which he died is an eternal moment, transcending time, covering every person who has ever lived or will live. But that moment also remains in time as the Eucharist–as his Eucharistic blood testifies.