If the ground is unstable builders have to drive pylons deep into the ground to give a solid base for the foundations to be laid upon.
Then they build upwards layer by layer, in alignment with the foundations. Once the shell of the building is complete they then work on making it pretty and inviting. If the foundations are wrong, any layers added won't line up properly, the building will start to show cracks and could eventually fall down.
If you are not secure and happy with yourself, if you are not living in alignment of what you want for you, then building a life on top of that will cause cracks to show.
If you are a shaky foundation the weight of any trials and tribulations will cause you to crumble and the whole thing will fall down around your ears.
You are the foundation stone that holds the rest of the life you build around yourself in alignment. Make sure before you start building upward the foundation stone is strong and solid.