According to the ecclesiastical authors, God with His good nature could not abide that the good belongs only to Him, and He created man in his image to benefit the man, too.
Divine love is the cause of human existence in the world, because real love is not an end in itself, but spreads to others.
There are many forms of love, which are expressed as selfish, sordid, relating to one’s own personality. But the highest expression of love is the trait to be spread, and divine love is the highest expression of this one. Such love is also sacrificial, even with the actions of self-sacrifice for the sake of others.
John the Evangelist is speaking about such love, showing the divine love for humanity. “God so loved the world, that He gave His only begotten Son, that whosoever believeth in him should not perish but have everlasting life. For God sent not His Son into the world to condemn the world, but that the world through Him might be saved” (3:16-17).
So with this love, Christ accomplished redemption and the salvation of humanity, and with that love, God granted the eternal life to man, gave the opportunity to inherit the kingdom of heaven.