From the perspective of Orthodox Christianity, human life begins at conception (meaning fertilization with creation of the single-cell zygote). This conviction is grounded in the Biblical witness (e.g., Ps 139:13-16; Isaiah 49:1ff; Luke 1:41,44), as well as in the scientifically established fact that from conception there exists genetic uniqueness and cellular differentiation that, if the conceptus is allowed to develop normally, will produce a live human being. Human life is sacred from its very beginning, since from conception it is ensouled existence. As such, it is “personal” existence, created in the image of God and endowed with a sanctity that destines it for eternal life.
We are fearfully and wonderfully made. The “wonderfully” is not difficult to see. It is the “fearfully” part that we need to recognize. If God is real, and He creates, should we unweave what He is weaving? If others have already taken embryos apart, should we then join in using the parts? I will grant that there is mystery here, and that should make us pause. We are right to be fearful, and it is better to err in the direction of guarding embryonic life.
It was Christ who left heaven and did not fear to become an embryo to become one of us. Or do we think he skipped that stage? It is Christ, as God-man, on the cross who stretches across from embryo to heaven connecting us from what we were to what we will someday be. Here is the value of the human embryo.Here we are rightly fearful.
Every human being is created by God, bears the image of God, and receives the gift of life in order to glorify God and to enjoy eternal communion with Him. Christian teaching, therefore, insists upon the sacredness of human life from its inception.