In Luke 14:25-33, Jesus is encouraging his followers to count the great personal cost it will take for each of them to truly be his disciple. He is trying to explain that in the very near future he is going to be crucified and in order for them to follow him to his death, they must be willing to die themselves. They would have to forsake everything (including family) in order to make this type of commitment to Jesus.
In order to get his point across, He uses two incredible examples that show how planning ahead of time can lead to a successful outcome.