Understanding the Importance of Following the Sunnah: Why Adhan and Iqamah Are Not Called Before Eid or Funeral Prayers

Question:

Why is it not permissible to call the adhan and iqamah before the Eid prayer or funeral prayer according to Islamic teachings?

Answer: 

To make it easier to understand, let's think and ask: can we call the adhan and iqamah before the Eid prayer or funeral prayer? The answer is definitely no, because the Prophet didn't do it; the Prophet didn't show an example. There was no obstacle for the Prophet to do it, but he didn't because Allah didn't command it. The Prophet didn't perform acts of worship unless taught and shown by Allah how to do it. So that's the religion the Prophet conveyed to us. 

But some people want to practice good deeds with the argument, 'It's just the adhan and iqamah, not music... it's a good thing, right? It can't be wrong...' Right and wrong are not based on what we feel, but worship must be based on the Prophet because he is the one who conveyed the religion. Following the Prophet ensures safety... 

That's why Allah tells us the stories of the Prophets and their disobedient people... their people were disobedient because they didn't want to follow their Prophets. What Allah commanded, they didn't do, but they sought other ways they felt were good to do. The characteristic of a believer is to hear and obey (sami'na wa ato'na)... those who frequently oppose the sunnah will regret it one day, as mentioned in Al-Furqan 27.