Can a non-Catholic person who believes that the consecrated host is the true Body, Blood, Soul and Divinity of Christ BUT is against the Catholic Church and her teachings receive communion?
In general, no. In some specific cases, yes for members of true Churches and yes with the bishop’s permission for members of Christian ecclesial communities.
Canon 844 §3. Catholic ministers administer the sacraments of penance, Eucharist, and anointing of the sick licitly to members of Eastern Churches which do not have full communion with the Catholic Church if they seek such on their own accord and are properly disposed. This is also valid for members of other Churches which in the judgment of the Apostolic See are in the same condition in regard to the sacraments as these Eastern Churches.
§4. If the danger of death is present or if, in the judgment of the diocesan bishop or conference of bishops, some other grave necessity urges it, Catholic ministers administer these same sacraments licitly also to other Christians not having full communion with the Catholic Church, who cannot approach a minister of their own community and who seek such on their own accord, provided that they manifest Catholic faith in respect to these sacraments and are properly disposed.
Ordinarily, non-Catholics and Catholics in a state of mortal sin may not receive Communion.
There are grave circumstances where a non-Catholic Christian may receive but simply believing in transubstantiation you cannot just go to Mass and receive.
CCC 1401 When, in the Ordinary’s judgment, a grave necessity arises, Catholic ministers may give the sacraments of Eucharist, Penance, and Anointing of the Sick to other Christians not in full communion with the Catholic Church, who ask for them of their own will,** provided they give evidence of holding the Catholic faith regarding these sacraments and possess the required dispositions.**
Simple question: Why would they wish to?
To ‘get’ God without having to do what Catholics do? Seems a bit selfish to me. . .
To be one with God because they have come to accept the Church’s true teaching on the Real Presence, yet they cannot accept anything further as true? This one’s a bit harder, because at least they wish for God, but again, it’s selfish. It’s like saying to God: "God, I really, truly believe that regular physical exercise for an hour daily, eating healthy foods in moderation, and regular daily prayer are essential for me to achieve a healthy mind and body .so because I TRULY BELIEVE THIS, please let me bypass the exercise and eating healthfully and praying, and just make me have the body I’d get if I DID spend all that time exercising and being healthy, without the work. "