John Gill Commentary John 6:54

"He that eateth my flesh and drinketh my blood hath eternal life: and I will raise him up at the last day." — John 6:54 (ASV)

Whoso eateth my flesh, and drinketh my blood
Spiritually by faith, as explained in the preceding verse:

has eternal life ;
the principle of spiritual life, which is evidently implanted in him, as appears from his eating and drinking; and is a durable and lasting principle: grace is an incorruptible seed; every part of it is abiding and permanent; and it is itself the beginning, pledge, and earnest of everlasting life, and is inseparably connected with it: moreover, such have eternal life itself, not only in Christ their head, but in themselves: they have a right unto it, and a meetness for it: and may be assured of it, as if they were personally possessed of it, from their election to it; the security of it in Christ; from the grace they have received, which is the beginning of glory; and the earnest of it in themselves:

and I will raise him up at the last day ;
to enjoy it in soul and body; (See Gill on John 6:39), (See Gill on John 6:40).