God Alone is Good
As we have emphasized over and over, God alone is good (Matt. 19:17; Rev. 15:4). There is no place or person in the universe where goodness may be found unless God is dwelling there. Divinity alone is good and as we recognize this, we will realize that the only way in which any creature may be good is if he is united to divinity. No creature is good in himself and therefore wherever there exists a creature who is not united to God, the only possible state of that creature is an evil state. By nature he is evil. There is no other option open to him.
This is what Lucifer, Adam and Eve and millions of angels did not realize when they chose to act independently of God, when they chose a path which separated them from God. In passing we should note that this happened while they all were in sinless flesh. It had nothing to do with their physical nature but had to do exclusively with a condition which developed in their minds. Immediately they became evil although this evil took time to manifest all its facets. Yet the consequences of Adam's actions were devastating for himself and his descendants. As a result of his choice, every one of his descendants was doomed to be born separated from God – a member of the kingdom of Satan, in a condition where Satan's principle of self, ruled, and where God's spirit was missing.
When we understand this, then we can see why every human being must be born again of the holy spirit. In the condition of our first birth we are not united to God. We are therefore totally evil, sinful in body and sinful in mind. All we are capable of is sin and sin and more sin. Our very best endeavours are laced with selfishness and are therefore intrinsically evil.
(Source: Restoration Ministry)