'Forever' in the Bible

The world is passing away, and with it its lusts [the shameful pursuits and ungodly longings]; but the one who does the will of God and carries out His purposes lives forever.

You know that He appeared [in visible form as a man] in order to take away sins; and in Him there is [absolutely] no sin [for He has neither the sin nature nor has He committed sin or acts worthy of blame].