The fruit determines who one is "born of".
Yes, and God can recognize whether the fruit is good or it is evil... and anyone to whom God has given "eyes to see" what kind of fruit it is.
An unrepentant soul won't receive the gift of the Holy Ghost.
While this is so, I do not believe gift the Holy Ghost is the final answer. It is rather the means God has given to men to allow them to attain what he wants them to attain. Whether or not they do is still up to them. When God gave men the gift of the Holy Ghost, He never removed from them the right to choose to follow the lead of the Holy Ghost or not. For this reason the apostle Paul wrote:
"Quench not the Spirit." I Thess 5:19
Why worry about the "fleshy vessel"?
I believe that each person has been made a steward over a part of God's property. That includes that "fleshy vessel". Because the vessel is dying and will eventually go back to dust mean we should abuse it with improper food or improper actions or inactions? God has "given" us many things, but they are still His. We will be judged according to how well we handled our stewardship. Even as stewards we may also be heirs, but an heir is not an owner until the land is signed over to him or until he has inherited.
"The righteous shall inherit the land, and dwell therein for ever." Psalm 37:29
"And if ye have not been faithful in that which is another man's, who shall give you that which is your own?" Luke 16:12
"He said therefore, A certain nobleman went into a far country to receive for himself a kingdom, and to return.
And he called his ten servants, and delivered them ten pounds, and said unto them, Occupy till I come.
But his citizens hated him, and sent a message after him, saying, We will not have this man to reign over us.
And it came to pass, that when he was returned, having received the kingdom, then he commanded these servants to be called unto him, to whom he had given the money, that he might know how much every man had gained by trading.
Then came the first, saying, Lord, thy pound hath gained ten pounds.
And he said unto him, Well, thou good servant: because thou hast been faithful in a very little, have thou authority over ten cities.
And the second came, saying, Lord, thy pound hath gained five pounds.
And he said likewise to him, Be thou also over five cities.
And another came, saying, Lord, behold, here is thy pound, which I have kept laid up in a napkin:
For I feared thee, because thou art an austere man: thou takest up that thou layedst not down, and reapest that thou didst not sow.
And he saith unto him, Out of thine own mouth will I judge thee, thou wicked servant. Thou knewest that I was an austere man, taking up that I laid not down, and reaping that I did not sow:
Wherefore then gavest not thou my money into the bank, that at my coming I might have required mine own with usury?
And he said unto them that stood by, Take from him the pound, and give it to him that hath ten pounds.
(And they said unto him, Lord, he hath ten pounds.)
For I say unto you, That unto every one which hath shall be given; and from him that hath not, even that he hath shall be taken away from him." Luke 19:12-26
