Are men descended from Adam
Yes, they are, and the Bible is truly a tale of two Adams.
Rom 5:12
Wherefore, as by one man sin entered into the world, and death by sin; and so death passed upon all men, for that all have sinned:
Rom 5:13
(For until the law sin was in the world: but sin is not imputed when there is no law.
Rom 5:14
Nevertheless death reigned from
Adam to Moses, even over them that had not sinned after the similitude of Adam's transgression,
who is the figure of him that was to come.
Rom 5:15
But not as the offence, so also
is the free gift. For if through the offence of one many be dead, much more the grace of God, and the gift by grace,
which is by one man, Jesus Christ, hath abounded unto many.
Rom 5:16
And not as
it was by one that sinned,
so is the gift: for the judgment
was by one to condemnation, but the free gift
is of many offences unto justification.
Rom 5:17
For if by one man's offence death reigned by one; much more they which receive abundance of grace and of the gift of righteousness shall reign in life by one, Jesus Christ.)
Rom 5:18
Therefore as by the offence of one
judgment came upon all men to condemnation; even so by the righteousness of one
the free gift came upon all men unto justification of life.
Rom 5:19
For as by one man's disobedience many were made sinners, so by the obedience of one shall many be made righteous.
Rom 5:20
Moreover the law entered, that the offence might abound. But where sin abounded, grace did much more abound:
Rom 5:21
That as sin hath reigned unto death, even so might grace reign through righteousness unto eternal life by Jesus Christ our Lord.
Adam was the figure or type (typos in the Greek) of him that was to come, and Christ is the antitype.
1Co 15:45
And so it is written, The first man Adam was made a living soul;
the last Adam was made a quickening spirit.
1Co 15:46
Howbeit that
was not first which is spiritual, but that which is natural; and afterward that which is spiritual.
1Co 15:47
The first man
is of the earth, earthy:
the second man is the Lord from heaven.
Jesus Christ is the last Adam and/or the second man.
The first man or the first Adam ushered sin and death into this world through his disobedience, and the second man or the last Adam ushered righteousness and eternal life into this world through his obedience.
It really is that simple.
Salvation is found in Jesus Christ who is the seed of Abraham (Galatians 3:16), and it has nothing to do with the ethnicities of those who place their saving faith in him.
Gal 3:26
For ye are all the children of God by faith in Christ Jesus.
Gal 3:27
For as many of you as have been baptized into Christ have put on Christ.
Gal 3:28
There is neither Jew nor Greek, there is neither bond nor free, there is neither male nor female: for ye are all one in Christ Jesus.
Gal 3:29
And if ye
be Christ's, then are ye Abraham's seed, and heirs according to the promise.
Col 3:9
Lie not one to another, seeing that ye have put off the old man with his deeds;
Col 3:10
And have put on the new
man, which is renewed in knowledge after the image of him that created him:
Col 3:11
Where
there is neither Greek nor Jew, circumcision nor uncircumcision, Barbarian, Scythian, bond
nor free: but Christ
is all, and in all.
Again, it is through Jesus Christ, the seed of Abraham (Hebrews 2:16), that all the nations of the earth can or will be blessed, and this is why God changed Abram's name to Abraham, which means "a father of many nations."
Act 10:34
Then Peter opened
his mouth, and said, Of a truth I perceive that God is no respecter of persons:
Act 10:35
But in every nation he that feareth him, and worketh righteousness, is accepted with him.