How are
>Enoch "seventh from Adam" (Jude 14),
>Noah "the eighth person, a preacher of righteousness" (2 Peter 2:5),
>and Christ "after the order of Melchizedek" (Hebrews 7)
?

How are both of the following faithfully called μονογενῆ (translated "only begotten" in the English translation) of Scripture:
>Jesus (John 3:16), who had half-siblings
>Isaac (Hebrews 11:17), who had half-siblings?
Yes, Christ did not have a father by the flesh, so "only begotten" makes sense for that case--but for Isaac as well? Isaac's father, Abraham, clearly had another child (Ishmael), yet Scripture refers to Isaac also as μονογενῆ, translated as "only begotten"? What does that word--μονογενῆ--mean?

Plus the usual questions.
"Is it faith or works?"
"Can a baby be saved?"
"Can the severely mentally retarded be saved?" (Sincerely, think about it.)
"Can someone lose their salvation?"
"How is this fair to someone who never heard the Gospel?" (Truly, consider the centuries and continents.)
"There are verses about believing and verses about those preordained, deceiving the elect if it were possible, etc.--How could one reconcile those? Do we choose to follow Christ--or are we destined?"
And, of course, tracing down the seed--stated from Genesis to Revelation.
The seed concept matters because it's wrapped up in the act of salvation. That's why it's so important to understand.

So let me start with something controversial:

It is not your goal to be saved.
You are called to be faithful, not to be saved (nor to save).
Our faithfulness is what will be judged.

You are already saved.

John 10:24-31
<<<emphasis mine>>>
>Then came the jews round about him, and said unto him, How long dost thou make us to doubt? If thou be the Christ, tell us plainly. Jesus answered them, I told you, and ye believed not: the works that I do in my Father's name, they bear witness of me. But ye believe not, because ye are not of my sheep, as I said unto you. My sheep hear my voice, and I know them, and they follow me: <<<And I give unto them eternal life; and they shall never perish, neither shall any man pluck them out of my hand. My Father, which gave them me, is greater than all; and no man is able to pluck them out of my Father's hand.>>> I and my Father are one. Then the jews took up stones again to stone him.

"Neither shall any man pluck them out of my hand." Not even you. Not even you can stop yourself from his having saved you.
"It is finished."

("But we know there are those who will be not saved! The tares! The antichrists!" Yes. Hold on. I'm still going over salvation. After that, we'll go over judgment.)

There are things salvation is and things salvation is not.

Salvation is
>life after the last day, when the wheat is kept and the tares are cast into the lake of fire for efficient destruction (not torture)--called the second death (for a reason: they cease to be) (hence why in Matthew we're warned to fear not one who can destroy the body but one can destroy both body and soul)
Salvation is NOT
>something Christ left unfinished; something you complete (neither by your faith nor your works); a conditional reward
>an everlasting life in heaven; an afterlife without a body
>the judgment of how your everlasting life will be after resurrection (there is such a judgment)

Salvation is life, simply. Not being destroyed.
That is the gift of equal measure, the grace undeserved for which no man can boast. That is the foundation.
Then there is individual reward. The judgment.
1 Corinthians 3:11-15
>For other foundation can no man lay than that is laid, which is Jesus Christ. Now if any man build upon this foundation gold, silver, precious stones, wood, hay, stubble; Every man's work shall be made manifest: for the day shall declare it, because it shall be revealed by fire; and the fire shall try every man's work of what sort it is. If any man's work abide which he hath built thereupon, he shall receive a reward. If any man's work shall be burned, he shall suffer loss: but he himself shall be saved; yet so as by fire.

This is true of the saved.
But who was saved?
And we know there are those who will not be saved (to be thrown into the lake of fire, destroyed).
Who are they?
This is why the seed question matters, and talking about that will also answer all of the example questions above. [I'll continue by a comment on this comment.]