IF quotes are from Amy Carmichael, who was a Protestant Christian missionary that served in India for 55 years without furlough and wrote many books about the missionary work there.
What does God owe mankind? Nothing! But, He offers them His love as if He does! He is not obligated on our part to love us. But He obligates Himself to do so. His natue is love, 1 John 4:8, "...God is love..." He can't deny that about Himself and He has put Himself in the position to extend to us what we don't deserve but what He can't hold back! It's His nature to love. Yes, He fulfilled that within the Trinity from eternity past. He is love and that was and still is His nature between Father, Son, and Holy Spirit. Yet, it was God's good pleasure (Revelation 4:11 KJV) to not only create mankind but to love them with His unconditional love. And in Christ He gives that to us without limit, Romans 5:5!
God hates sin but He loves the sinner. He is perfectly holy, yet He welcomes unholy people to come to the Cross and receive from Christ His perfect salvation. He takes their sin nature on Himself and then offers them His nature which is holy. He knows we can't live right, so He lives "right" through us. Without Him we're incapable of loving like He loves, yet with Him we can! And these are just a few of the "paradoxes" of His Love!