The purpose that God chose Nary was to save the world through Jesus.<quoted text>
God sent Jesus as His unique only begotten Son to do the Will of His Father God.
Only God Himself can fulfill the Will of God.
And only God Himself can give eternal life.
Jesus is the giver of eternal life.
If you do not believe in Jesus you will not have eternal life with God.
New King James Version (NKJV)
16 For God so loved the world that He gave His only begotten Son, that whoever believes in Him should not perish but have everlasting life. 17 For God did not send His Son into the world to condemn the world, but that the world through Him might be saved.
18 He who believes in Him is not condemned; but he who does not believe is condemned already, because he has not believed in the name of the only begotten Son of God. 19 And this is the condemnation, that the light has come into the world, and men loved darkness rather than light, because their deeds were evil. 20 For everyone practicing evil hates the light and does not come to the light, lest his deeds should be exposed.