Because God would. 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. " Exodus 20:13, "Thou shalt not kill(murder)." Parenthetic note added for understanding. Psalm 139:13-16, "For thou hast possessed my reins: thou hast covered me in my mother's womb. (14) I will praise thee; for I am fearfully and wonderfully made: marvellous are thy works; and that my soul knoweth right well. (15) My substance was not hid from thee, when I was made in secret, and curiously wrought in the lowest parts of the earth. (16) Thine eyes did see my substance, yet being unperfect; and in thy book all my members were written, which in continuance were fashioned, when as yet there was none of them." Romans 3:23, "For all have sinned, and come short of the glory of God." Revelation 21:8, "But the fearful, and unbelieving, and the abominable, and murderers, and whoremongers, and sorcerers, and idolaters, and all liars, shall have their part in the lake which burneth with fire and brimstone: which is the second death." Luke 13:3, "I tell you, Nay: but, except ye repent, ye shall all likewise perish. " Romans 5:7,8, "For scarcely for a righteous man will one die: yet peradventure for a good man some would even dare to die. (8) But God commendeth his love toward us, in that, while we were yet sinners, Christ died for us." John 3:16, "For God so loved the world that he gave his only begotten Son, that whosoever believeth in him should not perish, but have everlasting life." Hebrews 1:8, "But unto the Son he saith, Thy throne, O God, is for ever and ever: a sceptre of righteousness is the sceptre of thy kingdom. "
Psa 121:1-8 A Song of degrees. "I will lift up mine eyes unto the hills, from whence cometh my help. (2) My help cometh from the LORD, which made heaven and earth. (3) He will not suffer thy foot to be moved: he that keepeth thee will not slumber. (4) Behold, he that keepeth Israel shall neither slumber nor sleep. (5) The LORD is thy keeper: the LORD is thy shade upon thy right hand. (6) The sun shall not smite thee by day, nor the moon by night. (7) The LORD shall preserve thee from all evil: he shall preserve thy soul. (8) The LORD shall preserve thy going out and thy coming in from this time forth, and even for evermore."