When Does Life Begin?

In today's reading from Isaiah 49:1-7, the prophet states something that all Christians should also proclaim, that the Lord forms us in our mother's wombs.

Listen to me, O coastlands,   pay attention, you peoples from far away!The Lord called me before I was born,   while I was in my mother’s womb he named me.2 He made my mouth like a sharp sword,   in the shadow of his hand he hid me;he made me a polished arrow,   in his quiver he hid me away.3 And he said to me, ‘You are my servant,   Israel, in whom I will be glorified.’4 But I said, ‘I have laboured in vain,   I have spent my strength for nothing and vanity;yet surely my cause is with the Lord,   and my reward with my God.’
5 And now the Lord says,   who formed me in the womb to be his servant,to bring Jacob back to him,   and that Israel might be gathered to him,for I am honoured in the sight of the Lord,   and my God has become my strength—6 he says,‘It is too light a thing that you should be my servant   to raise up the tribes of Jacob   and to restore the survivors of Israel;I will give you as a light to the nations,   that my salvation may reach to the end of the earth.’
7 Thus says the Lord,   the Redeemer of Israel and his Holy One,to one deeply despised, abhorred by the nations,   the slave of rulers,‘Kings shall see and stand up,   princes, and they shall prostrate themselves,because of the Lord, who is faithful,   the Holy One of Israel, who has chosen you.’

Isaiah repeats the "formed in the womb" statement thus cementing its importance to the hearer of these words.

Woe be to those who destroy what God has formed and named.