The Cross tells us we are definitely guilty. It also tells us that if we repent, we are definitely forgiven. To take one and not the another, setting aside that the latter is a non sequitur without the former, is to cause ourselves to suffer from incurable shame, if we take only the former, or to cause others to suffer from our seared consciences, if we take only the latter.
The above is true, by the way, whether we accept the logic of vicarious sacrifice, as ancient Israelites did and as most present-day Christians do, or reject it, as Girardians do.