Sikhism developed from the spiritual teachings of Guru Nanak, the first Guru (1469–1539), and of the nine Sikh gurus who succeeded him. The tenth guru, Gobind Singh (1676-1708), named the Sikh scripture "Guru Granth Sahib" as his successor, bringing to a close the line of human gurus and establishing the scripture as the eternal, religious spiritual guide for Sikhs. Guru Nanak taught that living an "active, creative, and practical life" of "truthfulness, fidelity, self-control and purity" is above the metaphysical truth, and that the ideal man "establishes union with God, knows His Will, and carries out that Will". Guru Hargobind, the sixth Sikh Guru (1606-1644), established the concept of the mutual co-existence of the "miri" (political/temporal) and "piri" (spiritual) realms.