Why is holiness important for entering heaven?

Heaven is described as a holy city, and in Revelation 21:27, it is explicitly stated that no one who is defiled or sinful can enter. The character of God as holy and just necessitates that all who dwell with Him must also be holy. Thus, unless we are made holy, we cannot enter into heaven. In fact, the scripture asserts that even believers must be transformed, as the corruptible must put on incorruption, highlighting the importance of holiness as a prerequisite for entering into eternal life.