Everything that happens in our life is for the purpose of conforming us into His image. The whole purpose for man and life is to have fellowship with God; there's no other reason. Fellowship with God is why man was created. He's given us a lot of side jobs like ruling the planet, but that's not why we're here. He created us to fellowship with Him.

Fellowship was broken. The plan of redemption was to bring us back to that fellowship. You can't have that fellowship without sanctification. Without holiness no man shall see the Lord (Heb. 12:14).