In addition to the Middos that can be found in every person, there are also certain tendencies that are part and parcel of every Jew's makeup. Chazal tell us (Yevamos79a) that there are three simanim (features) that characterize the Jewish Nation - they are compassionate, bashful and performers of kindness. These are not specific Middos, rather, they are general features that can lead to many positive Middos, and a deficiency in these areas often brings numerous negative Middos in its wake.
Moreover, these three features are the root of the three most central aspects of Judaism - Torah, avodah and gemilus chassadim. In contrast, the three opposing negative tendencies lie at the root of the three cardinal sins - idol worship, adultery and murder.
Compassion is a tendency to connect to others, feel their difficulties and sympathize with them. The idea of avodah is to connect to Hashem and only one whose heart is open to connecting to others can hope to create a rapport with Hashem. The opposite tendency is that of achzarius (cruelty). Such a person is "ach zar" - entirely foreign, since he has no ability or interest in connecting to or understanding other people. Such a person feels entirely disconnected from the Creator, Who - as he surmises - most probably does not busy Himself with the mundane matters that characterize human beings. Thus, he turns to avodah zara, lit. a foreign service, i.e. the feelings of foreignness push him to toward a different type of spiritual service.
Bashfulness is defined as the tendency to hide not only one's weaknesses but also his qualities. The opposite tendency is brazenness. A brazen person looks to stand out. He's interested in focusing the spotlight on himself, thusly highlighting both his positive and negative characteristics. Someone who sets his focus internally can hope to learn the Torah which can be described as penimiyus of the physical world. In contrast, the brazen fellow whose eye is focused externally simply cannot connect to the Torah. The cardinal sin which is the antithesis of the Torah is adultery. One who commits giluy arayos has revealed something which is meant to be hidden.
A performer of kindness has the tendency to give and give some more. His love for giving is the quality needed to bring him to the third fundamental area in Judaism - gemillus chassadim - performing kind deeds. The negative parallel is the miser. He cannot bear to give anything to anyone, and he is focused solely on taking and thereby adding to his own stockpile. His intense aspiration to procure his desires can lead him to transgress the cardinal sin which stands opposite kind deeds, since he might even resort to murder if there is a person who stands in his way.
Every member of Bnei Yisrael was blessed with these three most wonderful predispositions. They prepare us for the proper performance of the Torah fundamentals and distance us from those sins which are abhorred by Hashem. With this in mind it is understandable why in Parshas Yisro, immediately following Kabbalas HaTorah, the Torah cautions us regarding the three cardinal sins, since they are diametrically opposed to everything the Torah stands for.
Yet, it is interesting to note just how the Torah refers to these three sins: Do not fashion the keruvim out of silver instead of gold for that is tantamount to idol worship. Do not build the mizbeiach with metal since knives are used for murder. Do not climb the mizbeiach with stairs since this causes one to broaden his steps, which is analogous to revealing one's nakedness (giluy arayos). When building the Bais Hamikdosh we must distance ourselves from the cardinal sins to the nth degree, because being cautious in these areas is the foundation of the entire Torah.
As we set out to rectify our middos, we should take a moment to appreciate just who we are. Each and every one of us has three innate features that set us on the correct path toward perfection. Our job is to take the potential and turn it into a reality, thusly living life the way it was meant to be lived!