Seriously, how is this even a debate? Jesus was clear on the validity of the Old Testament. There is room for interpreting the New Testament to mean denying the Old. Jesus was super explicit.
"Do not think that I have come to abolish the Law or the Prophets; I have not come to abolish them but to fulfill them. For truly I tell you, until heaven and earth disappear, not the smallest letter, not the least stroke of a pen, will by any means disappear from the Law until everything is accomplished. Whosoever therefore shall break one of these least commandments, and shall teach men so, he shall be called the least in the kingdom of heaven: but whosoever shall do and teach them, the same shall be called great in the kingdom of heaven. I tell you, unless your righteousness surpasses that of the scribes and Pharisees, you will not enter into the kingdom of heaven.“
Matthew 5:17-20
With that out of the way, who are the strange self-proclaimed Christians who deny the Old Testament? Are they dumb optics fags worried the normies will see the good book as bigoted or filthy sinners who don't want to follow natural law?