Why Protestants reject the Council of Nicaea.

The Council of Nicaea is a very useful apologetics tool beyond just discussing matters of the Trinity. What most people don't realize is that Nicaea produced more than just a Creed, it also issued 20 canonical laws which were binding on all Christians living at that time. The information contained in these Canons is just as useful (if not more so) as any Church Father when it comes to evaluating Protestantism against the bar of Church history. Below, I will mention why each of the 20 Canons are incompatible with all Protestantism in one way or another. This leaves Protestantism in a significant bind, because virtually all Protestants wholeheartedly affirm the Creed and deem the Council to be an orthodox testimony in early Christianity. After reading these Canons, the Protestant must recognize that they cannot embrace the Creed without also embracing the Canons, because if the Canons teach heresy and error, then the Protestant has no business at all embracing the Creed which this same Council produced. Protestants have no problem affirming the Catholic Church is correct on a lot of things, but they say the Catholic Church is false and cannot be trusted because it also teaches many errors. By this same logic, a Protestant must reject Nicaea as well, for Nicaea teaches many "errors" in its Canons and binds all Christians to these "errors" as well.

• Canon 1 says if a clergy (willingly) undergoes castration, he is no longer allowed to be a pastor. Yet I’m sure most Protestant clergy would have no problem undergoing sterilization, and moreover they wouldn’t let some council tell them what they can/cannot do with their own body.
  
  
• Canon 2 says baptism is “spiritual washing,” which doesn’t sound very symbolic, and warns against advancing a newbie into ordination to priest or to bishop. This doesn’t sound very Protestant to me.
  
• Canon 3 explicitly makes the three-fold distinction between the office of Deacon, Priest, and Bishop. Yet Protestants say there is only two offices (they deny priest), and I think Calvin said the three-fold distinction was blasphemy.
  
• Canon 4 says that anyone who is to become a bishop must go through a process of being appointed by other bishops and ratified by the Patriarch. This doesn’t sound very Protestant since Protestants practice self-ordination, wherein a person is a church leader because they want to be one, and as long as other people are willing to submit. They also reject the rank of Patriarch.
  
• Canon 5 says a person who has been excommunicated in one diocese is not to be admitted to another diocese. This doesn’t fit with the Protestant practice of "if you’re kicked out of one church, just go down the street to the next one that will accept you, or start your own".
  
• Canon 5 also makes mention of the liturgical season of Lent, which many Protestants consider tradition-of-men blasphemy.
  
• Canon 6 says the Bishop of Rome has real authority, ruling by "ancient custom" (i.e. long before AD325 at Nicaea). This is problematic for Protestants because it affirms a Bishop of Rome, the Pope, very early on in Church history and affirmed by the Council itself. If the Papacy is blasphemy, how can you accept this Council which endorses the Papacy?
  
• Canon 7 says the Bishop of Jerusalem should be honored because of his link to the Holy Land. This is problematic for a Protestant, because the Church is attaching special honorary affection to a place. (Which ironically, if Protestants say the Holy Land is still venerable because Jesus lived there, why isn’t Mary also venerable since Jesus lived in Her?)
  
• Canon 8 lays out regulations for accepting heretics back into the Church. This makes little sense in Protestantism where no such regulations exist (at least not outside tiny pockets) and no such standards by which to judge heresy.
  
• Canons 9 & 10 are about the Council’s authority to set the universal canonical requirements for ordination. Of course this is outrageous to Protestant sensibilities.
  
  
• Canons 11 & 12 show the Council has the authority to issue penances for serious sins, even stiff penances. Again, outrageous to Protestant sensibilities.
  
• Canon 13 speaks of “ancient canon law” and about those receiving the last rites, particularly “Viaticum” (receiving Eucharist on their deathbed). Receiving Eucharist outside of a liturgical service makes no sense in the Protestant mind, especially upon your death bed. This canon strongly implies the Eucharist was kept reserved in a Tabernacle somewhere and that it is a powerful spiritual gift, not a mere symbolic outward reminder of what Jesus has already done for you.
  
• Canon 14 speaks of the waiting period of catechumens (i.e. those converting to Christianity), meaning that that a person ordinarily didn’t just hear the Gospel and become Catholic immediately, they had to go through a mini-discernment process. Most Protestants object to the notion of “catechumen” and see it as the Catholic Church perverting the simple Gospel of simply accepting Jesus dying for your sins.
  
• Canons 15 & 16 say clergy are not allowed to move from city to city, and if they do they can suffer excommunication. This doesn’t square with the Protestant notion that there is no such thing as jurisdictions and that a pastor can go wherever he wants and preach wherever he wants.
  
• Canon 17 forbids Usury, that is making money off of a loan, and indirectly indicates a pastor shouldn’t be in any money making businesses. Most Protestants today would say there is nothing wrong with Usury, and indeed that a Pastor can also be a businessman on the side. Ironically, Protetant scholar Philip Schaf’s Nicene Fathers series says the following while commenting on this canon: “The glory of inventing the new moral code on the subject [of Usury], by which that which before was looked upon as mortal sin has been transfigured into innocence, if not virtue, belongs to John Calvin!” It was John Calvin who made Usury go from a mortal sin to a virtue, and this sin is the economic backbone of most Western/Protestant nations.
  
• Canon 18 speaks again of the three-fold distinction of Deacon, Priest, and Bishop, each of a different rank. See Canon 3 above.
  
• Canon 19 gives instructions on who is to be Re-Baptized, as well as speaks of women who have taken on a religious habit (e.g. a Nun). Both of these are contrary to Protestant sensibilities.
  
  
• Canon 20 speaks of universal liturgical regulations, including kneeling during Sunday Liturgy, and mentions the Season of Pentecost. Obviously, most Protestants don’t have liturgical regulations and don’t have a Season of Pentecost, since this is seen as unbiblical “traditions of men” imposed by Catholicism.
  

If you're a Catholic reading this, you need to recognize the apologetics treasure before you, and use it when talking with Protestants. If you're Protestant, you should be troubled by this historical testimony, as it not only goes strongly against Protestant sensibilities, this historical information is perfectly in line with Catholic sensibilities. Really, you cannot in good conscience remain Protestant and still accept Nicaea...but we also know you cannot in good conscience reject Nicaea, so the only solution is embracing historical Christianity, namely Catholicism.

UPDATE:
I'd like to include a brief mention of the Letter of the Council to the Church in Egypt. This is the only other known information the Council issued along with the Creed and the 20 Canons listed above. This Letter is found in the first link. Briefly, the Council was addressing a schism that happened in the 'diocese' of Egypt, hundreds of miles away from the city of Nicaea. The Council saw itself as authoritative enough to make a ruling on what was going on in Egypt, condemn the bad guys, and settle things. This is impossible under the Protestant framework, wherein no Council has such authority. The Council Letter also explains that an official date for celebrating Easter was set, so that all Christians would celebrate it on the same day. This goes against any Protestant framework in which no body has such authority.