As God commands us to pray continually, He also instructs us in many ways on why we must pray continually and warns us to pray so that we will not fall into temptation.
Just as regular breathing is not a difficult task for a person in a state of robust good health, a spiritually healthy individual finds it natural and does not find it arduous to live by God's Word and pray continually as usual. This is because as much as one prays, he will enjoy good health and all may go well with him even as his soul gets along well. The significance of prayer, therefore, could never be stressed enough.