Question: My friends tell me that the Marian apparitions are really the devil posing as an angel of light. If that were true why would "she" say that we should convert our lives and turn back to her Son? That doesn't sound like anything Satan would want us to do. How can this be from the evil one?
Answer Your friends could certainly be right. The Bible warns us: 'Satan himself transforms himself into an angel of light' (2 Corinthians 11:14). The word 'angel' (aggelos) means a messenger; and 'light' is symbolic of truth, righteousness and God Himself. Therefore, Satan, whom Jesus calls the father of lies, changes his form into the likeness of a messenger of God! He can certainly appear in the form of Mary and deceptively claim to come from heaven. So at least we should admit that some, if not all, of the supposedly Marian apparitions, could be deceptive apparitions of the Devil.
Even the Roman Catholic Church does not officially acknowledge every apparition as authentic. The Vatican approves some apparitions, but not others, and often there is no official directive.
Many devout Catholics give great importance to apparitions. It is all the more important that they should exercise great caution and discernment so that they would not be lead astray. Since the Devil's purpose is to deceive us, he would cleverly word his message in such a way that it would appear to be from God. It is not surprising that he would include such appeals to 'convert our lives and turn to her Son.' The old serpent speaks enough truth to sound credible, enough lies to poison his victims.
On the other hand, it should not be difficult to recognize the falsity in some of the messages if you know the Word of God. For example, Mary supposedly gave the scapular in an apparition. On it is written: "Whosoever dies clothed in this scapular shall not suffer eternal fire." What do you think about that pledge? Would you rest your eternal destiny on that promise? Do you think that by wearing two small pieces of cloth around your neck you will be certainly saved? Or would you rather trust the Word of God, which says that God so loved the world that He gave His only-begotten Son that whosoever believes in Him should not perish but have eternal life? (see John 3:16).
We need a message from heaven. We need God to answer our most important question: What must I do to be saved? Praise God, He has spoken. His answer is neither far away nor is it hidden. We have His inspired Word written in the Holy Scriptures, which are able to make us wise unto salvation which is by faith in Christ Jesus (please read 2 Timothy 3:15).
Since the Bible is sufficient for the purpose of showing us the way of salvation, we do not need any additional messages (not to mention the Bible's warning about Satan's deception). I would strongly advise you to hold on to what is written in the Scriptures. It alone is a sure and safe guide to Heaven.