Above all, one should look into the New Testament for the same. The Natural Law is also an eternal law, which determines what is considered to be good and evil. It could be discovered by reasoning and commanding men to carry out the will of God.
It is mentioned above that his theories could get confusing, or more like overlapping. He claimed that man is capable of only doing one thing that is attaining pleasure. But another view of his proves the above to be contradictory. He states that humans act in a way so as to generate the greatest amount of public happiness or general happiness, and also says that the determination of goodness and badness of their actions is their result expressed in the terms of public happiness. The stating of contradictory views like that shows us that he was not extreme in his thinking. Or rather his thinking wasn't really profound. Well, better than having an extreme view. Political Thought-Wayper.
Focusing on 'Treatise on Civil Government', he wrote it to disapprove the whole belief or doctrine of royal privileges or prerogatives. This book was basically about criticising Robert Filmer's 'Patriarcha'. He pointed out that parental power should be equal. Both the mother's and father's powers should be equally important. He also rebuked the power of monarchs by giving many metaphors including the Adam as one of the examples. .
Finally, in the 'Second Treatise on Civil Government', he said that men are naturally in the state of equality. He thought that all humans are born free. Also, a man's moral equality got nothing to do with his physical power and capabilities. He felt that they are morally equal if the reason inside them, makes them persons and somehow recognise those natural laws which define their rights and duties. Thus, Locke believed in the goodness of man, unlike Hobbes who thought all men are evil. Rational beings are called persons who have imbibed in them the gift of reason which enables them to understand and follow the law of nature.