God established a principle in the garden of eden that like begets like, "After its kind." This also holds true in the spiritual realm. The flesh can never give birth to something spiritual. What is the flesh? The flesh is, quite simply, all that a man is by birth, for, the flesh gives birth to flesh. Since our parents are flesh, all that they could produce was more flesh. Therefore, nothing that a man is by birth can produce a spiritual person! Neither the heredity of the flesh nor the will of the flesh nor the strength of the flesh can produce that which is spiritual; as it is written, the children of God are, "born, not of blood, nor of the will of the flesh, nor of the will of man, but of God." (John 1:13) Those whose profession of faith was prompted by the understanding of the flesh, the emotions of the flesh, or the actions of the flesh do not have a spiritual faith, but a fleshly faith. That is, he whose faith is merely the acknowledgement of true doctrine arrived at through a process of theological instruction and confessed before an assembly; and those of the free-will bent, whose profession is the result of a carefully crafted emotional manipulation at the end of a service; and those whose "regeneration" and "cleansing from sin" is accomplished through ceremonial observances such a baptism or the Lord's Table: these have nothing spirtual, for their religious observances are merely flesh, and cannot produce spiritual life.
What then is effective? "That which is born of spirit is spirit." Only spiritual things can give birth to other spiritual things. In the Scriptures, we find two spiritual things able to produce spiritual life. The first is God, Himself. "God is spirit..," says the Scriptures. He is the living, Personal agent in the production of all spiritual things. It is God, the Holy Spirit, who invades the hearts of His people and creates spiritual life there: "It is the spirit that quickeneth; the flesh profiteth nothing." ( John 6:63a) The second spiritual thing which creates spiritual life is the Word of God, as it is written, "the words that I speak unto you, they are spirit, and they are life." (John 6:63b) So James writes, "Of his own will begat he us with the word of truth." (James 1:18) These and these alone (God and His word) are able give birth to anything spiritual. If we would have life, then let us appeal to these. If we would win the souls of our loved ones, then let us preach God's Word and pray to God for them. No other means will work.