The Catechism in Questions & Answers

99. What is the significance of Jesus’ sacrificial death for us?

Through His sacrificial death, the Son of God established the way for sinners to be delivered from spiritual death and attain eternal life: “In this the love of God was manifested toward us, that God has sent His only begotten Son into the world, that we might live through Him. In this is love, not that we loved God, but that He loved us and sent His Son to be the propitiation for our sins”
(1 John 4: 9-10).

Spiritual death: see Questions 89. and 532.