Why did you give up your only son for sinners like us?

John 3:16 is where I would go for this.  “For God so loved, the world that he gave his only begotten Son that whosoever believes in him shall not perish but have eternal life.”

Also, 1 John 4:9-10 says, “In this the love of God was made manifest among us, that God sent his only Son into the world, so that we might live through him. In this is love, not that we have loved God but that he loved us and sent his Son to be the propitiation for our sins”.

God loves us!  That’s why he sent Jesus to die on the cross for our sins.  He wants us to place our faith and trust in Him in response to his love.  He desires your love in return for his.