receive Holy Communion one has to be a baptized Catholic, must have
made their First Communion, must believe in the Real Presence of Our
Lord in the Eucharist, must be in a state of grace, and must observe the
one hour fast before receiving. One must also be in union with the
Church; not rejecting any dogma or official moral teaching of the
Church. A person who does not meet all these criteria, should not
receive Holy Communion. If one is in a state of mortal sin, for example,
and receives Holy Communion, they are committing a sacrilegious
Communion, which is very detrimental to themselves. It is a grave sin.
Christ cannot remain within them, and so there is a saying that, “One
crucifies Christ anew by forcing Him into oneself”, where He cannot
remain and is not really welcome until the person has gone to confession
and been reconciled with God and His Church.