Before the destruction of the temple, all males over the age of nineteen were obliged to pay the temple tax annually. Checking the notes on this passage, it is unclear as to whether this passage applies to this time period after the destruction of the temple when the temple referred to was dedicated to the Roman gods. However, in some ways it has the same sense of rendering to Caesar the things of Caesar.
Jesus gives Peter the manner of securing the coin that will pay the tax. I'm sure that he wasn't telling us that we will find the money to pay our taxes by fishing, but rather that regardless of its use it is moral to pay our taxes to the government since the money also belongs to them.
It's kind of interesting how messages about a culture we don't understand, and is thousands of years ago, still has lessons for us today. In the United States, citizens and resident aliens who work and are paid are responsible for paying taxes to both the federal government and any state that charges taxes and sometimes to the local city government regardless of their status. There are actually exceptions and they are mostly related to the amount of income they receive. I'm not sure of the laws in other countries.
I'm aware that there are people who object to some of the ways taxes support, but that doesn't exempt them from paying. Governments have the right to make the laws and as long as they don't demand their citizens to perform sinful acts, they need to be obeyed as this is considered part of the commandment that asks us to 'Honor our Father and our Mother."
If we don't like what the government is doing, then we can work in legal ways to change the laws, and Jesus expects us to do just that when he tells us about our responsibility to work for justice for the poor and the vulnerable.
This is only one of the many ways in which the Bible helps us to live our lives as God would want.
