Altars are places where God and men/women meet. It's at the altar that we leave behind the things that hold onto us from our past and step into the promises of God.
In Joshua 3-4, we see the children of Israel finally make it into the promise land. From 430 years of slavery, to 40 years of wandering, now it was time for them to step into their potential.
Sometimes things hang on to us for generations but through the power of Christ we believe that you can walk in all that God has for you!