St. Dominic formed a group of men and went about preaching the truth in the manner of our Lord in the Gospels. They themselves lived poverty; they owned nothing and begged for their daily sustenance. In time. they were recognized as a religious order, he Order of Preachers also called Dominicans.
What helped immensely in St. Dominic's conversion of the Albigensians was a vision of our Lady. She appeared to him and showed him a wreath of roses which represented the rosary. Mary asked him to say the rosary daily and to encourage everyone to do the same. In saying this prayer, one had to meditate upon the fact that our Lord took on flesh (the Annunciation), that He was born, that his Body underwent the passion and that He rose bodily on the third day after his death. This led people to understand that the material realm was not evil and that conception and birth were good things. It is not the body that is bad, but the abuse of the body that is wrong.
Our Lady, the rosary and St. Dominic's persistence in his vocation transformed Europe. The heresy abated.
The rosary is a powerful prayer. Not only do we ask for our Lady's intercession, but we gain a greater insight into the mysteries of our holy Faith. We grow more rooted in what God has revealed which leads to even more love for Him.
St. Dominic is a help for us too. He is an example of accomplishing God's will by his obedience and fidelity. He can be our champion in praying for us so that we can do the same things that he did in our own little way. May each of us always have the desire to know God better and to share the truth with everyone.