In Christian theology, Satan is often depicted as a fallen angel who rebelled against God and was cast out of heaven due to his pride and desire to be equal to God. The concept of Satan being "good at the beginning of time" refers to his original state as a powerful and high-ranking angel before his fall from grace.
According to Christian beliefs, Satan's ultimate fate is often portrayed as one of eternal damnation and punishment in hell. The book of Revelation in the Bible describes a final battle between good and evil, where Satan is ultimately defeated and cast into the lake of fire for eternity.
The specific details of Satan's fate and the events that unfold in the book of Revelation are subject to interpretation and may vary among different Christian denominations and theological perspectives. However, the general consensus is that Satan will face judgment and punishment for his rebellion against God and his role in tempting humanity to sin.
Ultimately, the fate of Satan at the end of time is symbolic of the triumph of good over evil and the ultimate victory of God's kingdom. The concept of Satan's defeat serves as a reminder of the consequences of pride, disobedience, and rebellion against divine authority.