Is "mother earth" image Biblical or pagan?

 The term Mother Earth in modern times is associated with new-age paganism and environmentalism, and for this reason is largely distained by modern Christians. This was not always the case. The term was used in the Bible and church fathers as simply an acknowledgement that God made the human body from the earth, and we feed from the earth. Unlike in paganism, Biblical mother earth is not a goddess, or a conscious living being. Furthermore, the mother-earth imagery is a type of Mary itself, as I will show according to St Ephraim the Syrian.

One of the earliest allusions to 'mother earth' is found in Job 1:21

He said, “Naked I came forth from my mother’s womb, and naked shall I go back there. The LORD gave and the LORD has taken away; blessed be the name of the LORD!”--Job 1:21

Many versions omit translating shammah-- "there" or corrupt the verse to say simply "depart" however the Hebrew and Greek texts do not allow for this. Job speaks of going back to his mother's womb at death (ie burial) alluding to the earth as his mother.

Virtually every Bible commentary, be they Catholic, Protestant, or Jewish acknowledges Job here speaks of the earth as "mother."

Jewish: 

From my mother’s womb: the earth, “whence I was taken,” or actually, “my mother.”
and I will return there naked: He is not referring to the womb. What then is the meaning of “there” ? To the place of his return, for which he is destined, and he will not change the law, to return anywhere but to the earth. Therefore, it was not necessary to mention it--Rashi, Commentary on Job 1:21 Catholic:  Thither. To that earth from which all are taken. (Haydock) — Ista terra gentes omnes peperit & resumet demum. (Varro.) — Ut mater operiens. (Pliny, [Natural History?] ii. 63.) See 1 Timothy vi. 7. — As….done. Some copies of St. Jerome omit this, which is borrowed from the Septuagint. (Calmet)--Haydock on Job 1:21 But Job's words may be more elegantly understood of evil and sin thus: "Naked" was formed from the earth at the beginning, as if from a "mother's womb: naked to the earth shall I also depart;" naked, not of possessions, for that were a trivial and common thing, but of evil and sin, and of the unsightly shape which follows those who have led bad lives. Obviously, all of us human beings are born naked, and again are buried naked, swathed only in grave-clothes.--Clement of Alexandria, Fragment I, from his Catena, commentary on Job 1:21 c. AD 190 Calvinist (Protestant): And said, Naked came I out of my mother's womb, and naked shall I return {b} thither: the LORD gave, and the LORD hath taken away; {c} blessed be the name of the LORD.  (b) That is, into the belly of the earth, which is the mother of all. (c) By this he confesses that God is just and good, although his hand is sore on him. --Geneva Study Bible on Job 1:21 Pope Gregory the Great (c. AD 600) notes that Sirach 40:1 comments on Job 1:21 in his Moralia: But as the earth has produced all of us, we not unjustly call her our mother. As it is written, An heavy yoke is upon the sons of Adam from the day that they go out of their mother's womb, till the day that they return to the mother of all things. --Pope Gregory the Great, Moralia, Book II, On Job 1:21

Similar to Job 1:21, Psalm 139:13-15 has David speaking of being formed in the earth:

For it was you who formed my inward parts; you knit me together in my mother’s womb. I praise you, for I am fearfully and wonderfully made.   Wonderful are your works; that I know very well. My frame was not hidden from you, when I was being made in secret, intricately woven in the depths of the earth.--Psalm 139:13-15

Either David in verse 15 repeats verse 13 but calls his mother the earth, or he is speaking as if he, like Adam, were made from the earth. Either way, similar language is used.

There are similar passages in Ecclesiastes 12, 1 Timothy 6. 

Sirach 40:1 appears to be commentary on Job 1:21, or based on it, but more explicitly calls the earth "mother":

Hard work was created for everyone, and a heavy yoke is laid on the children of Adam, from the day they come forth from their mother’s womb until the day they return to the mother of all the living--Sirach 40:1

In addition, the Fathers occasionally called the earth "mother."

The Syrian Father, St Ephraim the Syrian makes a connection between Mary and the earth from which Adam was formed:

"Just as, because the bodies which themselves have sinned, themselves must also die. and the earth their mother was cursed, so because of this body, because it is itself the church, which is not corrupted, the earth was blessed from the beginning. For the earth is the body of Mary, the temple which received the seed...Because of the first mother who was cursed, the second mother was expressly named blessed"--St Ephraim the Syrian (c. 306 – 373) EC Arm 4, 15 (CSCI 137, Arm 1, pp.55-6) 

 The Greek bishop of Constantinople St John Chrysostom refers to the earth as mother:

The earth, you know, is our mother and provider; to it we owe our beginning and our growth; this is homeland and grave for us all alike--St John Chrysostom, Homily 2 on Genesis

The north African, Latin father, St Augustine speaks of the "womb of the earth"

How powerful is God, who has given different seeds to the womb of the earth, that they might make to spring up such various shoots, such beautiful trees!--Exposition on Psalm 145

The north African , Tertullian, the first major Latin speaking Christian apologist (til his delving into heresy) writes of the earth as mother and "mother nature", and says it was normal to speak of heaven as a father and earth as mother in the speech of the time:

But if Saturn were a man, he had undoubtedly a human origin; and having a human origin, he was not the offspring of heaven and earth. As his parents were unknown, it was not unnatural that he should be spoken of as the son of those elements from which we might all seem to spring. For who does not speak of heaven and earth as father and mother, in a sort of way of veneration and honour? Or from the custom which prevails among us of saying that persons of whom we have no knowledge, or who make a sudden appearance, have fallen from the skies? In this way it came about that Saturn, everywhere a sudden and unlooked-for , got everywhere the name of the Heaven-born. For even the common folk call persons whose stock is unknown, sons of earth.--Tertullian, Apology, chapter 10

And they are angry with us, too, because we call each other brethren; for no other reason, as I think, than because among themselves names of consanguinity are assumed in mere pretence of affection. But we are your brethren as well, by the law of our common mother nature, though you are hardly men, because brothers so unkind. At the same time, how much more fittingly they are called and counted brothers who have been led to the knowledge of God as their common Father, who have drunk in one spirit of holiness, who from the same womb of a common ignorance have agonized into the same light of truth!--Tertullian, Apology, chapter 39 c. AD 200

Greek Father, St Basil the Great, Commenting on Genesis and plant life: 

The fertility of the earth is its perfect finishing; growth of all kinds of plants, the upspringing of tall trees, both productive and sterile, flowers' sweet scents and fair colors, and all that which, a little later, at the voice of God came forth from the earth to beautify her, their universal Mother.--St Basil the Great, Hexaemeron (Homily 2)

 Greek speaking Egyptian Christian apologist, Origen: 

Moreover, even if the ants set apart in a place by themselves those grains which sprout forth, that they may not swell into bud, but may continue throughout the year as their food, this is not to be deemed as evidence of the existence of reason among ants, but as the work of the universal mother, Nature, which adorned even irrational animals, so that even the most insignificant is not omitted, but bears traces of the reason implanted in it by nature.--Origen, Contra Celsum, Book IV 

 Conclusion: 

Is calling the Earth mother pagan? Yes. Is it Biblical? Yes. As pointed out to me once, witches light candles, but so do Jews and Christians.