In Genesis, Exodus, Leviticus, Numbers, Deuteronomy and on and on the Bible speaks of sacrifice. The sacrifice of the blood of the lamb and goat, the sacrifice of blood at the alter the sacrifice of one life precious to us as the best,to be offered to God to be given unto Him. The thing or person most precious to us.
That was all before the Greatest Sacrifice of All, the Crucifiction, Death and Resurrection of Jesus Christ our personal Saviour. The ultimate sacrifice that paid all debt due by us for any and all sin every person in the world has ever or will ever commit. That is too big for my mind to imagine, that's why I guess it has to be 'imagined' in my heart.
That kind of love alone seems incomprehensible to us humans. When Christ ascended He left with us the Holy Spirit to fill our hearts and give us all we need to understand. All we need to reach Him and all we need to believe.
Your mind can't figure it out, or believe it or understand it but your heart can.