After Cain killed Abel the LORD said to him, “What have you done? Your brother’s blood cries out to me from the ground! (v10)

But there is a better word than the blood of Abel

If the Blood of Cain cried out to the LORD: Sin! Murder! Justice!…

the blood of Christ cries out for the Christian: Forgiveness! Acceptance! Salvation!

The question What have you done? turns into Look at what Christ has done!

[You have come] to Jesus, the mediator of a new covenant, and to the sprinkled blood, which says better things than the blood of Abel (Hebrews 12:24)

Jesus’ blood is still speaking in heaven where there is a Judge, who is God of all. Good news