Most of the answer exists in the previous question, but I would have to ask anyone who has this attitude to truly look at their lives. I doubt anyone who is honest with themselves, including the greatest saints, would ever dare to say that they did not have room for improvement.
All would agree that they could have lived their lives better and more perfectly. Our time on earth is a great opportunity to do good. It is a great opportunity to earn merit. Once we die, this opportunity is gone. The graces offered to everyone who asks with an open heart in Medjugorje, will change their life. The graces will strengthen you in your faith, and bring you to a closer relationship with Jesus and His Blessed Mother. There is no refuting this. It is simple truth.
The rosary is one of the most powerful weapons we have against satan, and Our Lady promises many graces to those who pray it. Praying the rosary is not repetitiously repeating prayers over and over again.
There are now twenty "mysteries" of the rosary, which we meditate upon while reciting the prayers of the rosary. Eighteen of these mysteries are taken directly from the bible and constitute three periods of Jesus life (birth, ministry, death, and resurrection). The last two mysteries are dogmatic and are truths of our Catholic faith. There is no greater way to gain knowledge and be drawn into a deeper understanding of Jesus' life than praying the rosary, since it is scriptural. I can't say enough about the incredible graces that come as a result of praying the rosary. Our Lady asks that we pray all 20 decades every day, and asks that every family pray 5 decades of the rosary as a family together as well as reading a small passage of the bible every day.
My favorite comeback to this is one I heard many years ago from one of the local guides, and it is: "Then satan has converted!". Scripture tells us that you will know by their fruits. And the fruits of Medjugorje are amazing. Over 30 million people have visited Medjugorje since the apparitions began in 1981.