Genesis 1:27 So God created man in his own image, in the image of God created he him; male and female created he them.  (28) And God blessed them, and God said to them, Be fruitful, and multiply, and replenish the earth, and subdue it: and have dominion over the fish of the sea, and over the fowl of the air, and over every living thing that moves upon the earth.

Jesus referred to this in Matthew 19:3-9.  He stated it as fact--because it is fact.

A reader asked the following questions:

27 So God created man in his own image, in the image of God created he him; male and female created he them.
28 And God blessed them, and God said to them, Be fruitful, and multiply, and replenish the earth, and subdue it: and have dominion over the fish of the sea, and over the fowl of the air, and over every living thing that moveth upon the earth.
Q1) At this stage Eve has not been born, why then does God tell THEM " Be fruitful, and multiply, and replenish the earth,

Q2) and why the word replenish, if they are the first to inhabit the earth.

Answer:

1) "... created he him; male and female created he them.  And God blessed them, and God said to them...  At this stage Eve has not been born, why then does God tell THEM...?"  Actually, at this stage, female Eve has been created, not born.  That is why God refers to Adam and Eve as them. 

2) " why the word replenish, if they are the first to inhabit the earth." this is a good question since some translations could have been more clear in the way that it translated this particular word. As you may know, the Old Testament was written mainly in Hebrew. This Hebrew word actually means to fill.

04390 מלא male' maw-lay' or מלא mala' (#Es 7:5) maw-law'

a primitive root; v; {See TWOT on 1195}

1) to fill, be full
1a) (Qal)
1a1) to be full
1a1a) fulness, abundance (participle)
1a1b) to be full, be accomplished, be ended
1a2) to consecrate, fill the hand
1b) (Niphal)
1b1) to be filled, be armed, be satisfied
1b2) to be accomplished, be ended
1c) (Piel)
1c1) to fill
1c2) to satisfy
1c3) to fulfil, accomplish, complete
1c4) to confirm
1d) (Pual) to be filled
1e) (Hithpael) to mass themselves against

These are the kinds of questions that are often brought up by Christians who are trying to stand with one foot in Materialism, Naturalism and Uniformitarianism and the other foot in Christ. The two cannot possibly be reconciled, so this causes much confusion.