The "Gloom and Doom" Warriors (Numbers Ch. 25, Jeremiah Ch. 1)

"Before I formed you in the belly I knew you, and before you left the womb I sanctified you; I established you as a prophet unto the nations...Do not fear them for I am with you to rescue you" (Jer. 1:5,8). G-d warns Jeremiah from underestimating his own powers in influencing his listeners.
Jeremiah's mission seemed to be to forecasting doom and destruction. He was sent to tell the Jewish people, as well as other nations, of the desolation and exile that would occur as a result of their sins. It is for this reason particularly that G-d has to strengthen him and assure him of his capabilites in terms of getting the message across. In contrast, the book of Isaiah is called the book of "comforting and consolation".

However, we find elsewhere in the Torah a definite advantage to the less subtle approach.  For instance, in Numbers Ch.25.  When the Jewish people sin with the Midianite women, Pinhas son of Elazar responds swiftly and directly. "He followed the Israelite man into the tent and pierced them both, the Israelite man and woman into her stomach - and the plague was halted..."(Num. 25:8). And although his response seems to be an act of rash and unwarranted cruelty, G-d testifies about him that he "turned back My [G-d's] wrath from upon the Children of Israel...I give him my covenant of peace...for him and his offspring...a covenant of eternal priesthood."(Num. 25:12-13). 

Pinhas' unique response was his way of letting the Children of Israel that they needed to return and fix their ways. His reward was an eternal covenant since his act made a permanent impact on the Jews. Unlike Moses' approach of awakening G-d's mercy on the people through his prayers, Pinhas went straight to the ones causing the problems and awakened them to repent. This kind of approach has an eternal impact on the environment and therefore its reward is an eternal covenant of priesthood.

We all have a unique approach to serving the Creator. When we share our viewpoint with others in a pleasant and non-judgemental fashion, we can bring about a real change, and therefore, an eternal impact.