Rashi, in his explanation of the mitzva of parah adumah, illustrates how each aspect of this mitzvah correlates to and rectifies, the sin of the golden calf. "And the kohain shall take a cedar branch, a hyssop, and wool dyed scarlet with the dye of a worm, and throw it into the fire of the burning heifer." Rashi explains that the cedar is the tallest of all trees and the hyssop is the shortest amongst them. This symbolizes that the "tall" one who was haughty and sinned should lower himself like a hyssop and a worm and he will be forgiven.
Rav Wolbe (Shiurei Chumash Parshas Chukas) notes, that the Torah is letting us know that sin begins with ga'avah - haughtiness. Likewise, when Bnei Yisroel complained about the manna and demanded that they be fed meat (Bamidbar 11, 20) Hashem sent them quail as a punishment. He said they would eat it, "Until it comes out of your noses and you are disgusted with it, for you have disgusted Hashem Who is in your midst." Rashi explains Hashem was telling them, that if not for the fact that He dwelled in their midst, they would not have become conceited to do all the things that they had done. It was their haughtiness that brought them to sin and ultimately led to their downfall.
If it would be possible for one to completely cleanse himself of ga'avah, and in its place instill humility, he would never come to sin. Our Sages enumerate seven things that bring one to commit a sin. They can be compared to an electric circuit - only when there is a connection is there light. So too, without these seven traits there is no circuit and current that arouses one to sin. The foremost of these seven traits is ga'avah. Without ga'avah it is not possible to sin. Rabbeinu Yonah refers to ga'avah as the plow of transgression - it cultivates sin and causes it to sprout.
Rav Wolbe states (ibid. Parshas Beha'aloscha) that although one must adhere to all halachos, he should be wary of taking on stringencies. If abiding by the stringency will bring him to become conceited that he maintains such a high level of spirituality, then he is better off without it. It was because Bnei Yisroel were on such a high spiritual level - they merited Hashem's Shechina residing in their presence - that brought them to ga'avah and led to their aveirah - "If I had not dwelled in your midst you would never have come to sin."
This is all said in regard to one's own trait of ga'avah. However, with regard to the ga'avah of others, we must have an entirely different outlook. Chazal (quoted in Rashi to Bamidbar 12, 5) tell us that we may praise someone partially when they are present and completely when they are not present. The Mashgiach explains that this is not because we are worried that the subject of our praise will become conceited, rather because effusive praise borders on flattery, which is prohibited. He elaborates, that Rav Yisroel Salanter said that although we must "run" from honor, with regard to another, we have to pour the honor on in great quantities. Though we should hold ourselves back from indulging in our desires and cravings, we should try to provide our friends with all types of delicacies.
Likewise, although ga'avah is one of the first and foremost impetuses for sinning, that should only be a concern with regard to our personal striving for greatness. However, with regard to others, although we must be concerned for their spiritual well being, we should not deprive them of pleasure due to such concerns.