In the psukim of nazir, the nazir is called a 'choteh' (hence brings a sin offering; for he is over-abstaining on muttar things) yet he is also called 'kadosh' (for he does hold back from the physical world). Which is it? Here are 3 answers...
1) It's a machlokes! This dispute finds its origins in the gemarra (look at ta'anis 11a closely). R' Elazar holds he is holy [and thus re-explain what 'choteh' connotations mean] whilst Shmuel holds he's a sinner. And the mefarshim on chumash argue around this point too.
2) It depends on his intentions. If he decided to become a nazir leshem shamayim he is 'kadosh;' otherwise he is a sinner (Rambam - hilchos De'os
3;1, Nezirus 10;14, Nedarim 13;23-24)
3) He is both a sinner and holy! On one level he is holy because he is holding back from material pursuits. But he has not reached the top level; the ability to use physical things to create spirituality and get closer to HaShem via using the physical world and uplift it. So looking down from that top level, he is called a 'choteh.'