The Avodas Yisrael zt'l (Netzavim) writes in the name of the Magid of Mezritch zt'l, "Tzaddikim, although they are very afraid, they trust in Hashem's salvation and kindness, and are determined to return to Hashem. Although their thoughts remind them of their aveiros, an indication of a kitrug in heaven, they steer their thoughts away from their aveiros to think about teshuvah, to leave the aveiros from now on. They accept the yoke of heaven and trust in Hashem's immense kindness."
The Sma'k writes that we wear white clothing, which resembles tachrichim so that the joy of Rosh Hashanah should be in the spirit appropriate for the awesome day of Rosh Hashanah.
According to the Raavad, one doesn’t recite שהחיינו on the shofar because of the fear of the judgment. Shulchan Aruch (584:2) states that it is customary for the person who blows the shofar to receive an aliyah. The Levush explains, לב משמחי ישרים 'ה פקודי, Torah makes people happy, and thereby, he will be able to blow the shofar with joy.
