Those who have meditated on om will not come back again. They will attain liberation at the end of this universe. After that, only god will ex ist, with god's power of mire for a long time. Time won't exist until the next creation. And being a follower of dante, believe such a thing is possible.
Swami Sarvapriyananda teaches the Katha Upanishad, one of India's most revered texts which is also a part of the Vedas. It is a collection of philosophical poems representing a conversation between the sage Naciketas and Yama (god of death). They discuss the nature of Atman, Brahman and Moksha(liberation).