"When Christ came as high priest of the good thing that are already here, he went through the greater and more perfect tabernacle that is not man-made, that is to say, not a part of this creation. He did not enter by means of the blood of goats and calves, but he entered the Most Holy Place once for all by his own blood, having obtained eternal redemption." (Hebrews9:11,12 NIV)
Jesus Christ is the sacrifice and the priest.
The Bible emphasizes the love of God, but at the same time, it repeats over and over about the horror of sin and the punishment of sin as consequence.
Not only is sin incompatible with God, but the sin itself is to rebel against God, and destroy God. Nor can the sin and its consequence be accepted by the sacred nature of God. "For the wage of sin is death" (Romans6:23 NIV)
As humans are called sinners, they are guilty and cannot stand before God. If we sees God, we will perish in a moment because of the holy glory of God.
God saw with love those who perish in sin, and wanted save them, so He sent Jesus Christ, His son to this earth. God laid all the sin of humans and the death as the punishment of the sin upon Christ who is the Son of God, and killed Him on the cross. The death of Christ on the cross was the death as the punishment of the sin which humans ought to have received. Christ died for our stead. The death of Christ saved and cleansed us.