D.L. Moody emphasizes the necessity of spiritual vitality in his sermon 'Spiritual Irrigation,' contrasting the feeble faith of Nicodemus with the transformative experience of the Samaritan woman at the well. He illustrates that true Christian life should flow abundantly like an artesian well, rather than requiring constant effort to extract spiritual nourishment. Moody points out that many believers lack spiritual power because they have not allowed the Holy Spirit to fill them, leading to a dry and ineffective faith. He encourages Christians to seek a deeper relationship with God, which will result in rivers of living water flowing from within them. Ultimately, he reassures that those who thirst for righteousness will be filled by God's grace.

It is possible a man may just barely have life and be satisfied; and I think that a great many are in that condition. In the 3rd chapter of John we find that Nicodemus came to Christ and that he received life. At first this life was feeble. You don’t hear of him standing up confessing Christ boldly, and of the Spirit coming upon him in great power, though possessing life through faith in Christ. And then turn to the 4th chapter of John, and you will find it speaks of the woman coming to the well of Samaria, and Christ held out the cup of salvation to her and she took it and drank, and it became in her "a well of water springing up into everlasting life." That is better than in 3rd chapter of John; here it came down in a flood into her soul; as some one has said, it came down from the throne of God, and like a mighty current carried her back to the throne of God. Water always rises to its level, and if we get the soul filled with water from the throne of God it will bear us upward to its source But if you want to get the best class of Christian life portrayed, turn to the 7th chapter and you will find that it says he that receiveth the Spirit, through trusting in the Lord Jesus, "out of him shall flow rivers of living water." Now there are two ways of digging a well. I remember, when a boy, upon a farm, in New England, they had a well, and they put in an old wooden pump, and I used to have to pump the water from that well upon wash-day, and to water the cattle; and I had to pump and pump and pump until my arm got tired, many a time. But they have a better way now; they don’t dig down a few feet and brick up the hole and put the pump in, but they go down through the clay and the sand and the rock, and on down until they strike what they call a lower stream, and then it becomes an artesian well, which needs no labor, as the water rises spontaneously from the depths beneath. Now I think God wants all His children to be a sort of artesian well; not to keep pumping, but to flow right out. Why, haven’t you seen ministers in the pulpit just pumping, and pumping and pumping? I have, many a time, and I have had to do it, too. I know how it is. They stand in the pulpit and talk and talk and talk, and the people go to sleep, they can’t arouse them. What is the trouble? Why, the living water is not there; they are just pumping when there is no water in the well. You can’t get water out of a dry well; you have to get something in the well, or you can’t get anything out. I have seen these wooden pumps where you have to pour water into them before you could pump any water out, and so it is with a good many people; you have to get something in them before you can get anything out. People wonder why it is that they have no Spiritual power. They stand up and talk in a meeting, and don’t say anything; they say they haven’t anything to say, and you find it out soon enough; they need not state it; but they just talk, because they feel it is a duty, and say nothing. Now I tell you when the Spirit of God is on us for service, resting upon us, we are anointed, and then we can do great things. "I will pour water on him that is thirsty," say God. O blessed thought - "He that hungers and thirsts after righteousness shall be filled!"