It's not the idea of God's wrath being appeased I don't like. It's the idea of God getting that upset in the first place, that his wrath would need appeasement at all, as if God were some bratty child that threw a temper tantrum if he didn't get his way. That is NOT the God whom Jesus came to preach about.
How do you feel about the OT then, because there are many incidents in where God became angry, even the word "jealous" has been used many times. Look at what he did to David because of his sin against Uriah.
II Sam 12:8 And I gave thee thy master's house, and thy master's wives into thy bosom, and gave thee the house of Israel and of Judah; and if that had been too little, I would moreover have given unto thee such and such things. 9
Wherefore hast thou despised the commandment of the Lord, to do evil in his sight? thou hast killed Uriah the Hittite with the sword, and hast taken his wife to be thy wife, and hast slain him with the sword of the children of Ammon. 10
Now therefore the sword shall never depart from thine house; because thou hast despised me, and hast taken the wife of Uriah the Hittite to be thy wife. 11 Thus saith the Lord, Behold, I will raise up evil against thee out of thine own house, and I will take thy wives before thine eyes, and give them unto thy neighbour, and he shall lie with thy wives in the sight of this sun. 12 For thou didst it secretly: but I will do this thing before all Israel, and before the sun. 13 And David said unto Nathan, I have sinned against the Lord. And Nathan said unto David, The Lord also hath put away thy sin; thou shalt not die. 14 Howbeit, because by this deed thou hast given great occasion to the enemies of the Lord to blaspheme,
the child also that is born unto thee shall surely die
David is refereed to as man after God's own heart, yet he paid a heavy price for his sins, losing not only that child, but also 3 other sons, maybe because he said the man in Nathan's story should have to pay the lamb back fourfold.
God's justice rendered this punishment, and David was later forgiven. Christ paid the punishment for us, in dying for the sins we committed, enabling us to be forgiven. God's justice says there must be a punishment because of what sin "earns" (Rom 6:23), yet he allowed another to take that punishment for all. Justice was still served, yet through Christ's love for the world, He paid it for us.
Jn 15:13 Greater love hath no man than this, that a man lay down his life for his friends. 14 Ye are my friends, if ye do whatsoever I command you
I do see how this could also apply with some of the others, but it seems to me to make the most sense as a penal substitution. Sin has a price that must be paid. His death paid it, his blood able to continue cleanse those who apply it.
Heb 9:20 Saying, This is the blood of the testament which God hath enjoined unto you. 21 Moreover he sprinkled with blood both the tabernacle, and all the vessels of the ministry. 22 And almost all things are by the law purged with blood; and without shedding of blood is no remission