It is not something that exists eternally but rather part of creation. The first line of the Bible states that heaven is created along with the creation of the earth (Genesis 1). It is primarily God's dwelling place in the biblical tradition: a parallel realm where everything operates according to God's will.
14:1 Pursue love, and earnestly desire the spiritual gifts, especially that you may prophesy. 2 For one who speaks in a tongue speaks not...
Slaves, obey your earthly masters with fear and trembling, with a sincere heart, as you would Christ, not by the way of eye-service, as...
The bible presents the challenges and choices of Abraham when it came to trusting the promises of God, believing in hope, hoping against hope...