Have you ever noticed how a dog is always hungry? Even if we fed our dogs only an hour ago, they are ready for more food if we will offer it. But there is a limit beyond which a dog is satisfied. My father used to have a rather large dog which stayed in our back yard. On this dog's birthday, daddy bought several cans of dog food. The first can was inhaled in about five seconds. The second can was offered to the dog about five minutes later. It disappeared quite rapidly. Five minutes later the third can was opened. It took a little longer, but it was eaten. The fourth can was eaten rather slowly. Finally, when my father opened the fifth can and called, the dog simply laid in the back yard and wagged his tail. He did not bother to try to eat any more. He was satisfied.
Jesus said: "Blessed are those who hunger and thirst for righteousness, for they shall be satisfied" (Mt. 5:6). Hunger and thirst are two of the strongest drives known to mankind. What you have an appetite for will be the determining factor deciding with what you will be filled. If you are extremely thirsty, you will probably fill yourself with water. If you have an overpowering desire for chocolate candy, you will probably eat some.
It is significant that Jesus uses hunger and thirst to illustrate how much we ought to strive for righteousness. If you really want to be a righteous person who obeys God and lives a life of godliness and purity, that will be the result. You will be able to overcome temptation. You will not be distracted by inferior goals. If you want your life filled with spiritual goodness, God will not hold back what you need. Just as my father was able to give his dog all the food he could want, God can satisfy our spiritual longing. God is able. The only question is: "Do we long for God?" (Ps. 42:1-2).