I disagree here...Of course we disagree on many things theological so it will come as no surprise...
What the so-called experts have to say is meaningless to me...What the bible says is the key...
The argument your church uses is that there are two natures, one of God and one of man...
The unregenerated man has but one nature...That of his father, Satan...We, like God, have a body, a soul and a spirit...We are made in the likeness of God...A trinity...These entities are inter-connected...
At salvation, we are regenerated and undergo an operation;
(Col 2:12 Buried with him in baptism, wherein also ye are risen with him through the faith of the operation of God, who hath raised him from the dead.
Col 2:13 And you, being dead in your sins and the uncircumcision of your flesh, hath he quickened together with him, having forgiven you all trespasses;)
We have a circumcision...A Spiritual circumcision, made without hands...Our soul and spirit is separated from our flesh;
(Col 2:11 In whom also ye are circumcised with the circumcision made without hands, in putting off the body of the sins of the flesh by the circumcision of Christ:)...
Our flesh is separated from our soul and spirit;
Heb 4:12 For the word of God is quick, and powerful, and sharper than any two-edged sword, piercing even to the dividing asunder of soul and spirit, and of the joints and marrow, and is a discerner of the thoughts and intents of the heart.
So when Jesus showed up, his flesh had the 'sinful nature' of man because that is man's only nature...
But Jesus the man, being God, was able to overcome ALL temptations...And He was tempted in everything...Sexy women, booze, money, power; just as we being filled with God (the Holy Spirit) can overcome ALL temptations if we listen to God...
When Jesus hung on the cross, his human body died...His blood fell on the ground...His old nature died...And it was not his old nature that was ressurected...
Just the same as your body when it rises up and heads for heaven;
1Co 15:51 Behold, I show you a mystery; We shall not all sleep, but we shall all be changed,
At Jesus' ressurection, he put on a new body, as we will do at our physical ressurection...
In heaven, God has one nature...Just as we will have one and the same nature...
I know that's not Catholic church, but that's Bible...
Let's just leave it at this: Jesus is one Person, not two. Can we start there?