How Christ-like an act is is a pretty good measure of how morally right it is, wouldn't you say?
Or would you?
To be a good measure, "Christ-likeness" must be a quality that is always proportional to moral rectitude, and it must be a quality that can actually (if not literally) be measured.
But what does "Christ-like" mean? I think as it's used it has one of two meanings: more often, it means "similar to Jesus as He was in His public life"; less often, "animated by Christ's Spirit of love." And I think there's an important difference between the two meanings, despite the fact that of course in His public life Jesus Himself was animated by His Spirit of love.
Is "similarity to Jesus as He was in His public life" a quality that is always proportional to moral rectitude? If "similarity" connotes the idea of acting as Jesus acted in a similar situation, then I think the answer is no, for several reasons.
First -- and we really shouldn't lose sight of this -- Jesus is God, and we aren't. If someone pleads for my help, I oughtn't to reply, "My son, your sins are forgiven."
There are other, related reasons -- Jesus had a different mission, He lived in different times under different circumstances, and so on -- that all boil down to this: We are not Jesus, and aren't supposed to be Jesus. We are supposed to let Him live in us, to make us perfect, not to re-perfect a Galilean carpenter.
But there's another reason doing now what Jesus did then isn't necessarily the best choice, which is also the reason measuring the similarity to Jesus as He was in His public life is often impractical and even impossible: We know Jesus as He was in His public life almost entirely from the Gospels, and the Gospels don't do a very good job of portraying Jesus as He was.
They tell us a lot of things that Jesus did and said, but very little about how He did and said them. Often enough it's not entirely clear why He did and said things. The Gospels do not provide a psychological portrait of Jesus, so any attempt to transport Him to the here and now, to answer what Jesus would do, necessarily involves a certain amount of invention, of filling in details as they make sense to us.
The result is that what is said to be "Christ-like" in the sense of "like Jesus was," to be "Jesus-like" if you will, tends to be speaker-like. If I value a sense of humor, then my portrait of Jesus contains a strong sense of humor, and it's absolutely Christ-like to tell that joke; it might even be Christ-like to call the people who don't think that joke should be told whited sepulchers. How I value informality will inform how Christ-like I think a particular priest is while he offers Mass.
Overall, then, I don't think similarity to Jesus in His public life is a great measure of moral rectitude. What He did isn't necessarily what we should do, and what we think He would do isn't necessarily true either.
What about the other meaning of Christ-like, "animated by Christ's Spirit of love"? It's certainly a quality that is always proportional to moral rectitude. Can it actually be measured? Sure, by someone animated by Christ's Spirit of love. For someone like me, though, who is not particularly Christ-like, it can be tough to accurately judge how Christ-like many actions are, at least when they aren't clearly animated by something other than love.