“The famous Ratha-yäträ of Çré Jagannätha, Çré Baladeva and Çré Subhadrä-devé is held in Puré in the month of Äñaåha (June- July). At that time, those who are dedicated to dharma flood in from all corners of India and descend on Puré en masse.” Bhaktivinoda Thakura, Jaiva-dharma
There are few levels of understanding of this main festival in Puri. Some say that the main meaning of Ratha-yatra is in the following fact: Anyone who sees Lord Jagannatha (literally, Jagannatha means the Lord of the Universe) and ends his life under the wheels of His chariot, will go immediately to the spiritual world, on Vaikuntha planet. But this understanding is quite different from what is really told in the scriptures of India.
Never the less, every year millions of people from India and, recently, from all over the world are coming by all different reasons for the festival of Jagannatha, Baladeva and Subhadra. This festival is conducted during millions of years as it is said in the Vedas, Puranas and Upanishadas. And every year, like for the first time, we see how smoothly, slowly, swaying out of ecstatic emotions Jagannatha is coming out, walks and enters His chariot. His eternal brother and sister, Baladeva and Subhadra, come out first.
All millions of people walk with Them to the Gundica temple, celebrate all different festivals while Their Lordships are staying in Gundica for the few days and then walk Them back to the main temple. Being in Puri during the festival, I have heard how elevated Indian Vaisnava saints, sadhus, explain the deep meaning of Ratha-Yatra. Quoting the Vedas they describe the reason why we always see Baladeva’s chariot first, then Subhadra’s and only then, Jagannatha’s.
Jagannatha cannot but cares about all living beings, including all those who are not allowed to enter in His temple. Therefore, once a year He invents the pretext of being sick and desires to walk around on chariots when He gets better. In this way He gives to everyone the opportunity to serve Him and showers His mercy on all by giving His darshan. Hindus believe that anyone who sees the Lord Jagannatha on the chariot will never have to take birth again.
I have told you about Gundicha temple. In order to reach the perfection of life, we need guidance. All information we get from some authorities. And the Vedas tell that Baladeva is the personification of the original Guru, spiritual master. It is not possible to progress in spiritual life without Guru, therefore Baladeva goes first. Guru gives bhakti, the process of developing one’s love to the Supreme Lord and the love itself at the end. Subhadra is Bhakti-devi, so She goes after Baladeva. Bhakti purifies our hearts and prepares them for the Lord to sit. And only when our hearts are ready for the arrival of the Supreme Lord, there comes Jagannatha, the Lord of the Universe.
Personally, I love this explanation and so I share it with you here.
Ratha-Yatra starts very early with all different ceremonies, then dancers come out around 9 in the morning and only then Baladeva does. He is decorated with a huge flower crown and He sways out of spiritual ecstasy almost like Krisna-Jagannatha. When Baladeva is about to enter His chariot, Subadra comes out of the temple and then Jagannatha appears. The crowd roars overwhelmed by spiritual feelings. Heat. Personnel with syringes. Rescuers who carry out those fainted due to excessive sun. All of this builds up and suddenly you see Their Lordships on the chariots, being newly decorated and served. Then chariots start.
Afternoon. It seems, that people drag the chariots by ropes but in fact, when you touches this rope, you can feel that the rope drives you and chariot pushes you from behind. Usually chariots come to Gundica in the evening, then they stop there for a night or two. Thakurji are giving Their mercy. First day is over.
 Dharma means duty, in this case religious or spiritual duty of the soul.