Insufficient on its own. That is not the full gospel.
Look at His commands regarding Holy Eucharist in John 6.
John 6:
35Then Jesus declared, “I am the bread of life. He who comes to me will never go hungry, and he who believes in me will never be thirsty. 36But as I told you, you have seen me and still you do not believe. 37All that the Father gives me will come to me, and whoever comes to me I will never drive away. 38For I have come down from heaven not to do my will but to do the will of him who sent me. 39And this is the will of him who sent me, that I shall lose none of all that he has given me, but raise them up at the last day. 40For my Father’s will is that everyone who looks to the Son and believes in him shall have eternal life, and I will raise him up at the last day.”
. . .
53Jesus said to them, “I tell you the truth, unless you eat the flesh of the Son of Man and drink his blood, you have no life in you. 54Whoever eats my flesh and drinks my blood has eternal life, and I will raise him up at the last day. 55For my flesh is real food and my blood is real drink. 56Whoever eats my flesh and drinks my blood remains in me, and I in him. 57Just as the living Father sent me and I live because of the Father, so the one who feeds on me will live because of me. 58This is the bread that came down from heaven. Your forefathers ate manna and died, but he who feeds on this bread will live forever.” 59He said this while teaching in the synagogue in Capernaum.
Many Disciples Desert Jesus
60On hearing it, many of his disciples said, “This is a hard teaching. Who can accept it?”
61Aware that his disciples were grumbling about this, Jesus said to them, “Does this offend you? 62What if you see the Son of Man ascend to where he was before! 63The Spirit gives life; the flesh counts for nothing. The words I have spoken to you are spirit[e] and they are life. 64Yet there are some of you who do not believe.” For Jesus had known from the beginning which of them did not believe and who would betray him. 65He went on to say, “This is why I told you that no one can come to me unless the Father has enabled him.”
66From this time many of his disciples turned back and no longer followed him.
67”You do not want to leave too, do you?” Jesus asked the Twelve.
68Simon Peter answered him, “Lord, to whom shall we go? You have the words of eternal life. 69We believe and know that you are the Holy One of God.”
70Then Jesus replied, “Have I not chosen you, the Twelve? Yet one of you is a devil!” 71(He meant Judas, the son of Simon Iscariot, who, though one of the Twelve, was later to betray him.)