Is shaving your beard a sin? So no haircuts or trimming our beards? We see this interpretation of scripture at times and it makes you wonder. I had the same question and its a good one.
With that said, since Yeshua (Jesus) took the sins of the world upon Himself and took the punishment for those sins, and since scripture says God is the one who will judge all mankind, then its not our job to punish adulterers and the like. If people in the assembly continue in sin then they are to be cast out.. In other words God has given everyone the opportunity to repent. And as others have mentioned there is no ruling court, the Messiah has not returned, etc. etc.
As for wearing side burns (not cutting the corners of one's beard) I have found something interesting. Its not about not getting a haircut.
Leviticus 19:27 says "you shall not shave around the sides of your head, no shall you cut the edges of your beard".
But does this mean we can't shave or trim our side-burns or get hair cuts? No, and here is why.
The Hebrew word for shave or cut is naqaph H5362 which means to strike off, with violence, to destroy, etc. We also know that when we follow God we are not supposed to use the ways of the pagans ref. Deut 12:4.
So how did the pagans petition their gods? Lets look at 1 Kings 18. Elijah was confronting the prophets of Baal. Elijah challenged the false prophets in verse 23 & 24...
"choose one bull for themselves, cut it in pieces, and lay it on the wood, but put no fire under it; and I will prepare the other bull, and lay it on the wood, but put no fire under it. 24 Then you call on the name of your gods, and I will call on the name of the Lord; and the God who answers by fire, He is God.”
Well, if you are not familiar with the account, the prophets of Baal verse 26 says "called on the name of Baal from morning even till noon, saying, “O Baal, hear us!” But there was no voice; no one answered. Then they leaped about the altar which they had made.
27 And so it was, at noon, that Elijah mocked them and said, “Cry aloud, for he is a god; either he is meditating, or he is busy, or he is on a journey, or perhaps he is sleeping and must be awakened.” 28 So they cried aloud, and cut themselves, as was their custom, with knives and lances, until the blood gushed out on them. 29 And when midday was past, they prophesied until the time of the offering of the evening sacrifice. But there was no voice; no one answered, no one paid attention."
So we see that the pagans would cut and harm themselves in hopes that their false gods would answer their prayers due to their devotion. Or that they would memorialize certain events within their religion. When we study ancient pagan ways we also see people who tore out their hair to get their gods attention or when they were in mourning. We even see religions doing this today.
However, that is NOT what the One true God tells us to do.
So I personally think that God was not telling people to NOT get a haircut or to NOT trim their beards, but rather to not use the ways of the pagans when they presented their requests to god/s or memorialized any of their deeds.
With that being said, many people will interpret Lev 19:27 as a way to disprove those who follow the Torah and walk in the commandments of God. Most Christians have been told that the law was done away with at the cross and anyone who practices the old ways (Sabbath, Feasts, dietary instructions, etc.) have gone back under the curse of the law. The argument is that if you get a haircut or trim your beard you are committing a sin, so that proves the Torah observant believer is sinning, thus disproving his/her actions and beliefs, and that as believers today we are free from the law of sin and death. However when we know the background of the pagan cultures of the times, we see that God did not want us to harm ourselves when we pray or observe His mighty act like when He delivered the mixed multitude out of Egypt. After all we are citizens of His kingdom, His children, His bride and He would NEVER command us to harm ourselves like the pagans did/do.
Something to think about.