Tim Keller in King’s Cross, p. 168
It bears repeating: All love, all real, life-changing love, is substitutionary sacrifice. You have never loved a broken person, you have never loved a guilty person, you have never loved a hurting person except through substitionary sacrifice.
Jesus in Idaho Falls 
“Substitution” is one thing, and as far as that goes, this quote is correct. (However, it is worth noting that my doing something on behalf of another, something worthy of the name “sacrificial love”, may be more salvific for me in the end than for the person for whom it is done: “it is more blessed to given than to receive.” Obviously, we cannot say the same thing of Christ.)
But substitution implies neither “satisfaction” nor “penal” nor any similar term. We are saved by Christ, first and foremost, not from the Father’s wrath, but from the enemies of both humanity and God: sin, death, Satan. We are freed from the world, the flesh, and the devil, and yes, while Christ has done the heavy lifting, we cannot make this so great salvation our own without, in the words of St. Paul, “putting to death the deeds of the flesh”. We must “make our calling and election sure” and “we must purify ourselves”. This begins by our “obeying the gospel” and all that entails, within the context of the Church, in terms of participation in its sacramental life.
And, the process, we will indeed “bear each others burdens and so fulfill the law of Christ”.
Greg, Keller entitled one of his chapters, “The Cup”. And this chapter provides a section discussing God’s wrath.
“Your conception of God’s love–and of your value in his sight–will only be as big as your understanding of his wrath.” p. 178
Btw, did you hear about the LDS philospher, Richard Sherlock, who officially announced his crossing over into Catholicism?
RE: first comment. Sorry, I don’t buy it. Authentic love cannot be connected with wrath. Pain, yes. The cross indeed shows that.
Regarding the conversion: No, I did not, Todd, but thanks for the heads-up.