Oliver in Oliver Twist is a thoroughly good character as Dickens' goal was to show how goodness could be be sustained through a life of tragic adversity and triumph in the end due to a change in situation as a result of unaltered goodness. Oliver has very few moments in the story when he acts in a way that might be contrary to goodness, such as running away to London, but even these are based in goodness because they are motivated by a higher good, such as self-defense, which is what prompted him to run away.
Since Oliver embodies uncorrupted inner goodness and actions based on a higher order of good, some might say he represents the historical figure of Jesus who is the emblematic embodiment of goodness. Yet Jesus too acted in ways that went contrary to overt goodness, for example, when he crashed the goods in the sacrifice market at the Temple and whipped the merchants away from the Temple steps or when he castigated and verbally condemned the Jewish religious leaders for being "vipers" and for misleading the Jewish people.
However, Dickens himself doesn't suggest that he intends for Oliver to be recognized as any historical moral figure; he only claims Oliver is the representation of goodness that triumphs despite rampant social ills:
"I wished to show, in little Oliver, the principle of good surviving through every adverse circumstance, and triumphing at last."
he relates to many saints