Both. As the image of God, human beings certainly are capable of goodness and, in fact have good in their nature, but being a sinful creation born into a sinful world, our nature has been corrupted with evil. It is by the grace of God that human beings have not lost the goodness in them and many, even of those who do not know God, are good-natured individuals, but it is also a testament to the corruption of sin that otherwise good people do horrible things to themselves or those that love them. Message me for better explanations or with questions you might have, as there is only so much I can write in this forum.