State religions, are the majority belief in that nation, to say no would be an abuse of the faithful. That doesn't mean that there is no separation of church and state, often quiet the opposite, look at Russia, state religion is Russian Orthodox, and yet the church and the government are quiet separate. This has nothing to do with the government telling what you can and cannot do but is about respecting those who still make up a significant, if not the majority in countries like the United States.
State religions would contradict the Constitution and would cause civil dispute and unrest. The United States Constitution says, ". . . Shall make no law respecting any establishment of religion, or the free exercise thereof." Federal law and legislation has always overridden state laws. If we allow this to happen then it would create another minority and set the United States' social progress back, and send us in the wrong direction. It would send an unwelcoming vibe to religious minorities.
States absolutely should NOT be allowed to declare official religions. In this country, we have freedom of religion, which means that all people are allowed to practice their own religion without any hindrance. If you start declaring an official religion, what's next? Laws about that religion or any other religion? No. Keep the church out of the government.
If states started declaring official religions than the minorities of other religions will feel like outcasts and unwanted. In the long run that could cause issues, like riots, and fights to prove their religion is worth be recognized. It would be unfair to make them feel this way, and cause a lot of problems.
Many people have forgotten the principles that America was founded on, freedom of speech, right to bear arms, etc. Many people have willingly handed over their freedoms such as being able to change the TV channel if an inappropriate movie comes on. Instead of making up their own minds, many people would rather let the government tell them what to watch, when to watch and how to watch. If the states are allowed to declare official religions, then the next logical measure by the state is them telling you that you are only allowed to worship in a specific place and in a specific way, even if it goes against your beliefs. From that point, things begin to deteriorate very rapidly. After the states picks a religion, the will only allow individual to worship God in the way they say we should. Next, if you choose to not worship what the state demands you worship, they will begin to administer pubic punishments, or the state may take away your right to buy groceries and then you are left with the choice of abandoning the way you worship and conform to the state. You will be told where to worship, how to worship, etc and as time progresses, public humiliation and punishment will not be enough anymore the state will being with public executions instead or torture and life in prison. What I find the scariest thing of all is that the Bible, Gods holy word, prophesied about these things, things that are happening right now. We are experiencing hurricanes, earthquakes, tsunami's and many other natural disasters. We are also losing touch with each other because everyone has their face fixated on mobile phones and texting instead of talking to others in person.
If our freedom of religion is taken away from us and given to the state, that would be just the beginning on our path to slavery by the Government. Read the following passage from your bible and see what it means to you personally and how the state could ultimately affect your relationship with Jesus.