What is “Pure and Undefiled Religion Before God?
With the existence of so many differing religions, with their varying beliefs and practices many have been led to believe that a specific religion is unimportant. Just have a spiritual, worshipful attitude toward some spiritual power or powers that is superior to man and is able to affect one’s present and future life. They are convinced that no true religion as stated in the title above really exists. This idea that no true religion exists is constantly promoted and supported by religious leaders, who have lost respect for the word of God which teaches there really is a “pure and undefiled religion” established and sanctioned by God and the one He expects all men to follow. 
Many people view religion as simply some religious faith or institutional system of religious attitudes, beliefs and practices, developed in the minds of men. Thinking there is no true religion and seeing the existence of so many differing religions with various and often conflicting beliefs and practices, people feel free to choose the particular faith system or religion they wish to follow, one in which they will feel comfortable. Others simply reject all religions. They refuse to follow any since they don’t want to be committed to some religion they feel has been designed by human reasoning.
People who believe the things written above are wrong in their thinking. For, in the midst of the multitude of false, vain religions there does exist one true religion, and it is the only one that pleases God. For those who believe God and His word this one true religion exists today. It is the pure, undefiled religion designed by God for those wish to worship and serve Him. It is the only religion that God will accept. This true religion is Christianity.
James in his epistle, in Jas.1:26-27, draws a contrast between the pure, undefiled religion that God wants, as opposed to the vain religions of men. He writes, “If anyone among you thinks he is religious and does not bridle his tongue but deceives his own heart, this one’s religion is useless. Pure and undefiled religion before God and the Father is this; to visit orphans and widows in their trouble, and to keep oneself unspotted from the world.” While James does not fully define all the differences between the two, he contrasts any vain religion (that which has no real substance, and is empty, false and deceptive) v.26 with the pure, undefiled religion with which one rightly approaches God v.27. Christianity is that pure, undefiled religion that pleases God.
While it is true the word “religion” (GK “threskeia”) in the text basically refers to external aspects of religious worship and ceremonial service, it does not exclude the fact that while God has authorized and requires the divine rituals of worship and service (such as baptism for the remission of sins, the Lord’s Supper, singing, praying, giving Acts 2:41-42; Col.3:16), exercising these activities must come from an obedient heart. Jesus made this clear in His condemnation of the Pharisees in Matt.6:1-18. Their practice of religion was not heart-felt, thus unacceptable to God. Their practices were not genuine for they were only done for show, “to be seen of men.” Their hearts were not in their practice.
James, with two adjectives in v.27 shows that true religion before God is not a mere formality, but a life changing force. The true religion “before God” is one that is “pure” and “undefiled.” Pure is that which is clean, sincere, true. One cannot be religiously pleasing to God if the religion is not offered from a heart that has been purified by the blood of Christ Matt.5:8; 1.Pet.1:22-23. True religion must also be undefiled, uncontaminated and  uncorrupted with sin, one that remains separate from the allurements of the world. V.27; Gal.2:20. James also points out that one’s religious worship and service is to be directed “toward God,” and not toward men. See Jn.4:24. So, the true religion with which God Is pleased, and the only one He will accept is one that is pure and undefiled and offered to Him. It is a religion that is sincere and real, not practiced for pretense and show. 
Yes, I truly believe Christianity is the pure, undefiled religion that pleases God, the one that is revealed in God’s word, not the corrupted Christianity designed by men. When one performs the external rituals prescribed by God in His word, one must be careful to do the acts from a heart seeking to please God, not as an exercise to be seen of men.
Considering the things just written, I think of Matt.7:21. “Not everyone who says to Me, ‘Lord, Lord,’ shall enter the kingdom of heaven, but he who does the will of My Father in heaven.” Underneath what Jesus says here He is reminding people that He did not come to make people religious. The world was already religious, filled with religious people, Jews and Gentiles, who were religious. But they were following the wrong kinds of religion. What Jesus came to do was to correct people’s false religions and teach them God’s true religion, His pure and undefiled religion. Jesus taught this so people could become religiously right before God.  
The only ones who practice “pure and undefiled religion before God” are His people, who have been made so through His Son, Jesus Christ. These are those who with an obedient faith Rom. 1:5, are baptized into Christ Gal.3:26-27; Rom.6:3-5. They then become “a chosen generation, a royal priesthood, a holy nation, His own special people, that you may proclaim the praises of Him who called you out of darkness into His marvelous light; who once were not a people but are now the people of God, who had not obtained mercy but now have obtained mercy” 1.Pet.2:9-10.   Tommy Thornhill