Wasting the day

You can pray for something that God has no intention of doing in your life.  Jeremiah 29 speaks to this cause.  Jeremiah says that it will be seventy years before God brings them out of Babylon free.  That was a hint to put your efforts somewhere else.  You aren't coming out until he says you are coming out.  God told them to marry, and give their daughters in marriage.  He told them to pray for Babylon because their peace is now your peace.  Notice, that he did not tell them to pray to be free.  There was an appointed time to be free, there was no need to pray for something God already answered.  To pray anything other than God's will is simply wasting the day.