There is no mention in the Christian Bible about abortion, and at different times early Christians held different beliefs about abortion. However the debate is legitimate on the life of an unborn child. Historical and denominational views differ on the stage at which an unborn child is considered to be human, at which point it is considered an equivalent to murder to terminate its life.
Does the unborn child have rights that ought to be protected, as much as those of humans already born? Views also differ on the merits of certain exceptions where abortion is biblically fitting (e.g. on the grounds of a mother’s health).
the 1st Century A.D., Greeks influenced Christian ideas about
abortion. Greeks held the belief that early in gestation a fetus has
the soul of a vegetable and only later in gestation does the soul become
“animated” as the result of “ensoulment.” For the Greeks, ensoulment
occurred 40 days after conception for male fetuses and 90 days after
conception for female fetuses.  Consequently, abortion was not
condemned if performed early.
Between the 2nd Century A.D. to 4th Century C.E., several Christian philosophers condemned women who had an abortion. From the 5th to 16th Century A.D., Christian philosophers had varying stances on abortion. St. Augustine wrote that an early abortion is not murder because the soul of a fetus at an early stage is not present. St. Thomas Aquinas, Pope Innocent III, and Pope Gregory XIV believed that a fetus does not have a soul until “quickening,” or when a woman begins to feel her fetus kick and move. Abortion before quickening was, therefore, acceptable. Pope Stephen V and Pope Sixtus V opposed abortion at any stage of pregnancy.
Eastern Orthodox views on abortion
Eastern Orthodox Church believes that life begins at conception, and
that abortion (including the use of abortifacient drugs) is the taking
of a human life. However, it is acceptable in a few circumstances. The
Basis of the Social Concept of the Russian Orthodox Church states that
while abortion can never be seen as morally neutral, in some cases
economy can be used:
In case of a direct threat to the life of a mother if her pregnancy continues, especially if she has other children, it is recommended to be lenient in the pastoral practice. The woman who interrupted pregnancy in this situation shall not be excluded from the Eucharistic communion with the Church provided that she has fulfilled the canon of Penance assigned by the priest who takes her confession. 
The document also acknowledges that abortions often are a result of poverty and helplessness and that the Church and society should “work out effective measures to protect motherhood.”
Protestant views on abortion
Protestant views on abortion vary considerably. Christian fundamentalist movements unanimously condemn abortion, while mainstream Protestant traditions take more nuanced positions, but are generally pro-choice with some exceptions. Several mainstream Protestant traditions belong to the Religious Coalition for Reproductive Choice. These include the Episcopal Church, the Presbyterian Church (USA), The United Church of Christ, The United Methodist Church, the Unitarian Universalist Church, and the Lutheran Women’s Caucus.
Fundamentalist (Evangelical) movements: Fundamentalist Evangelical views on abortion
churches that include the Evangelical, Non-denominational, Southern
Baptist and Pentecostal movements, do not have a single definition or
doctrine on abortion. While these movements hold in common that abortion
(when there is no threat to the life of the mother) is a form of
infanticide, there is no consensus within these camps as to whether
exceptions should be allowed when the woman’s life is in mortal danger,
or when the pregnancy resulted from rape or incest. Some argue that the
lives of both woman and child should be given equal consideration, in
effect condemning all abortion including those performed to save the
life of the woman. Others argue for exceptions which favor the life of
the woman, perhaps including pregnancies resulting from cases of rape or
History within the Southern Baptist Convention – views on abortion
Before 1980, the Southern Baptist Convention advocated for abortion rights. During the 1971 and 1974 Southern Baptist Conventions, Southern Baptists were called upon “to work for legislation that will allow the possibility of abortion under such conditions as rape, incest, clear evidence of severe fetal deformity, and carefully ascertained evidence of the likelihood of damage to the emotional, mental, and physical health of the mother.” W. Barry Garrett wrote in the Baptist Press, “Religious liberty, human equality and justice are advanced by the [Roe v. Wade] Supreme Court Decision.”
History in the larger Evangelical movement
Randall Herbert Balmer, Ph.D., argues in his book, Thy Kingdom Come, that contrary to the popular belief that anti-abortion sentiments galvanized the fundamentalist evangelical movement, what actually galvanized the movement was evangelical opposition to the American Internal Revenue Service (IRS) after the IRS stripped the evangelical Bob Jones University of its tax-exempt status for refusing to allow interracial dating and marriage. It was not until 1980 that the evangelical movement came to oppose abortion.
Mainline Protestant churches’ views on abortion
Anglican Communion views on abortion
Positions taken by Anglicans across the world are divergent although most would refrain from simplifying the debate into “Pro Choice” or “Pro Life” Camps. The Church of England, for example, shares the opinion held by the Roman Catholic Church. In a 1980 statement, the church declared, “In the light of our conviction that the foetus has the right to live and develop as a member of the human family, we see abortion, the termination of that life by the act of man, as a great moral evil. We do not believe that the right to life, as a right pertaining to persons, admits of no exceptions whatever; but the right of the innocent to life admits surely of few exceptions indeed.”
The Episcopal Church in the United States of America has taken a pro-choice stand and has passed resolutions at its triannual General Convention that supports woman’s right to choose. The church opposes any government action that limits a woman’s right to choose this includes parental notification. The ECUSA does condemn abortions for sex selection and also condemns violence against abortion clinics. Like most mainstream Protestant denominations the Episcopalians allow the use of birth control.
The Anglican Church of Australia does not take a position on abortion.  However, in December 2007, an all-woman committee representing the Melbourne diocese recommended that abortion be “decriminalised”, on the basis of the ethical view that “the moral significance [of the embryo] increases with the age and development of the foetus”. This is seen to be the first official approval of abortion by Australian Anglicans.
Methodist Church’s views on abortion
The United Methodist Church upholds the idea that church doctrine should not interfere with secular abortion laws. In light of grave or socio-economic circumstances, the Methodist church believes in the right of the mother to choose whether to have an abortion, and is thus often regarded as pro-choice.
Presbyterian Church views on abortion
The Presbyterian Church generally takes a pro-choice stance. In their 204th General Assembly, they affirmed the following:
There is [both] agreement and disagreement on the basic issue of abortion. The committee [on problem pregnancies and abortion] agreed that there are no biblical texts that speak expressly to the topic of abortion, but that taken in their totality the Holy Scriptures are filled with messages that advocate respect for the woman and child before and after birth. Therefore the Presbyterian Church (U.S.A.) encourages an atmosphere of open debate and mutual respect for a variety of opinions concerning the issues related to problem pregnancies and abortion. The church ought to be able to maintain within its fellowship those who, on the basis of a study of Scripture and prayerful decision, come to diverse conclusions and actions.
Unitarian Universalist Church views on abortion
The Unitarian Universalist Church strongly supports abortion rights. In 1978, the Unitarian Universalist Church passed a resolution that declared, “…[the] right to choice on contraception and abortion are important aspects of the right of privacy, respect for human life and freedom of conscience of women and their families.”
United Church of Christ (UCC) views on abortion
The United Church of Christ has strongly supported abortion rights since 1971 as a part of their Justice and Witness Ministry. The church is an organizational member of the National Abortion and Reproductive Rights Action League (NARAL).
Roman Catholicism views on abortion
The Roman Catholic Church today firmly holds that “the first right of the human person is his life” and that life is assumed to begin at fertilization. The equality of all human life is fundamental and complete, any discrimination is evil. Therefore, even when a woman’s life appears jeopardized, choosing her life over her child’s is no less discrimination between two lives – and therefore morally unacceptable.  Catholics who procure or participate in an abortion suffer ipso facto latae sententiae (automatic, literally by that very fact the sentence is incurred) excommunication under Canon law, provided that the person knows of the penalty at the time the abortion occurs. The Roman Catholic Church also considers the destruction of any embryo to be equivalent to abortion.
According to the memorandum written by Cardinal Joseph Ratzinger, Catholic politicians who campaign and vote for permissive abortion laws should be warned by their priest to refrain from taking communion or risk being denied the Eucharist until they change their political views.
Catholics for a Free Choice
Catholics for a Free Choice was founded in 1973 “to serve as a voice for Catholics” who believe individual women and men are not acting immorally when they choose to use birth control, and that women are not immoral for choosing to have an abortion. Catholics for a Free Choice believe:
Catholic support for legal abortion is grounded in core principles of Catholic theology, which respect the moral agency of all women. It is bolstered by respect for the religious freedom and rights of people of all faiths and no religious faith, by respect for plural and tolerant democratic societies and, most importantly, by adherence to the Catholic principle of standing with the poor and marginalized of the world who are disproportionately women.