They might be seen to move very slowly in the water. We might also see some other smaller chunks of ice floating in the water near the iceberg. If we watched closely, we might see something unusual. Sometimes the smaller pieces of ice might be floating in one direction, while the iceberg floats in another. This is because the great icebergs reach far down into the water and are guided by the ocean's current while the smaller pieces of ice are pushed around by the wind and the surface waves.
People are like that.
Some people live very shallow lives. They just do what everybody else does. But there are other people whose lives go deep. They have come to know God through Jesus Christ. They are guided by the deeper currents of God's Spirit.