Read the preamble. They are absolute, if they are not, they mean nothing.
The Preamble to the Constitution does not have legal standing, it is not law. The Constitution is law. As such the Constitution and the Amendments can be changed. In some cases it will only take a decision by the Supreme Court to change the meaning of virtually anything in the Constitution. A future court may decide that the Heller decision was wrong and decide that the Second Amendment to the Constitution allows fire arms only to those in well regulated militias. That then would be the law of the land.