Is John Locke contradicting himself?

Locke believed the people are born in a blank slate or that we do not have innate knowledge. But on the other hand, he reasons human nature is naturally good that's why absolute power is unnecessary. If Locke believes that we do not have innate knowledge, then shouldn't that mean that human nature is not naturally good because it's in a blank slate when we are born? Because that would mean that goodness is an innate knowledge? I'm really so confused about it.