Protestants and Catholics both would consider that a heresy. It was one of the errors addressed by the Nicean Creed. "Who, for us men for our salvation, came down from heaven, and was incarnate by the Holy Spirit of the virgin Mary, and was made man;" See also the Anathemas of the Second Constantinople Council (553).
If your church is teaching that Christ was not wholly God and wholly man, you probably belong to a cult, and should try a Bible based faith.
I am a member of a cult with one member..
Wholly god and wholly man is a good question...
What is man but a spirit riding a Donkey(body)?..
Same with Jesus.. a Spirit riding a donkey..
The Donkey is one thing and Spirit is another.. Same is true for Jesus AND Us.. When a Donkey(body) dies the spirit goes somewhere else.. It is quite easy for God to make another conduit(body) for the spirit to inhabit.. That is if a conduit(body of some sort) is needed at all.. it is possible that a conduit is not even needed, except here on this planet..
The Universe is a big place.. a body would be a pain in the keyster..
"What eye has not seen, and ear has not heard, and what has not entered the human heart, is what God has prepared for those who love him." 1Cor 2;9