Humans DO have what we might identify as goodness in them, but unfortunately that's not the ringing endorsement it might seem. Scripture tells us that man was originally created very good and that we were made in God's image. Since God is perfectly good, this image bearer purpose manifests itself in acts of what would be called goodness in the common vernacular; we (tend to be) kind to children, we (usually) don't kill people that irritate us, we long for peace in the world.
All of these things are good things. The place where Christianity divides with most other religions comes with the demand not that humans simply "have goodness" to be pleasing to some higher power, but that they "be good" through and through. We can certainly perform good acts or have good thoughts, but these are only shadows at this point, remnants of our original nature before the corrupting influence of sin.
According to Romans 1, while we might have this or that moral accomplishment to point to compared to the subjective standard of one another's behavior, we each fall woefully short of God's objective standard of Goodness. In fact when compared to His objective standard of perfection, the situation is so bad that not only is our cumulative nature sinful (missing the mark God has set) but it has so far corrupted each individual action we take or thought we have that nothing we do is acceptable in His sight. Yes, we (usually) don't kill irritating people, but sometimes humans do - and even when we don't we are angry with them (and God has said that His standard is so impossibly high that even unnecessary anger is as bad as murder in His sight). We (tend to be) kind to children, but usually when it costs us very little or is not too much trouble, and it's usually more for the pleasure we get from their gratitude or some sense of communal obligation than simply a desire to be kind; and all this says nothing of the horror that adults have all to often been guilty of committing upon children.
This is the fundamental crux of the Gospel appeal, we have some goodness still in us and it earns for still more goodness, for the final victory of goodness even; but we are on the whole unacceptable ourselves in the light of that same goodness and so it only by appealing to the substitutional goodness of another that we can ever hope to enter into that future victory. Apart from Christ all my good works are as filthy rags, but He has taken the penalty for all my failings and so washed me clean and what's more has given me a perfect righteousness with which to clothe myself so that I can stand before Him one day at the restoration of all things.
The same offer is available to all, but we have to first accept that merely possessing some goodness is not the same thing as being good, and that however much we might point to isolated examples of the former in our lives we cannot achieve the latter on our own.