John 6:54, Flesh…blood. This is a Hebrew idiom for “the whole person” (see Matt 16:17; 1 Cor 15:50; Gal 1:6; Eph 6:12; Heb 2:14). This relates to Moses’ instructions that “man shall not live by bread alone…but by every word that proceeds from the mouth of YHVH” (Deut 8:3).
This applies to Yeshua who was that Word of Elohim who “became flesh and dwelt among us” (John 1:1 and 14). When one puts their faith in Yeshua (John 6:29 and 5:24), then one must also believe him—that is, not only accept him as the Son of Elohim and one’s Savior, but also follow and obey (or “eat”) him who is the Living Manna-Word of Elohim from heaven.
This involves believing his words by loving him and keeping his Torah-commands (John 14:15, 23 cp. Exod 20:6), which are his literal words. This is why YHVH instructed the Israelites to eat the whole Passover lamb, and to leave nothing left over (Exod 12:10).
This teaches us that we are to “eat” all of Yeshua—his whole Person as represented by the bread and the wine at communion on Passover. We are to accept the totality of his Word, not just the parts that suit us, or fit with our conventional religious viewpoints as per the traditions of men.
Many claim to eat all of his flesh and drink all of his blood, yet through their anti-Torah theologies they rip pages out of their Bibles and toss them into the spiritual trash can claiming it is for the Jews and not for them.
This is exactly what Adam and Eve did when they listened to the serpent’s lies at the tree of knowledge and rebelled against YHVH’s clear commands. The Bible defines sin as violating the words, commands or Torah of Elohim (1 John 3:4). It is also a sin not to believe in Yeshua (John 16:9; 3:18–19) who is the Living Torah-Word of Elohim incarnate. It is also sin to act in unrighteousness (1 John 5:17). The Bible defines unrighteousness as violating YHVH’s Torah commands (Ps 119:172), which are the words of Yeshua. In summary, when we accept all of Yeshua by eating his flesh and drinking his blood, (i.e., partaking of the bread and wine at communion) we are confessing that we accept the totality of who he was and is.
If we fail to believe and obey all of his words, then to the degree that we do so we are walking in sin, don’t love him and don’t even know him (1 John 2:3–4).