The unsaved are spiritually dead. Thats why they must be born again. If they died having come=on tinted to be in a state of unbelief (having never recieved christ) they will remain in this dead state for eternity
Born again is a change in body not in the mind. Jesus says in John 3: 3 Jesus answered and said unto him, Verily, verily, I say unto thee, except a man be born again, he cannot see the kingdom of God.
Notice verse 3, except a man is born again, he cannot see the kingdom of God. We have just learned something here. If you are not born again you can not see the kingdom of God.
But Paul talks about being renewed in likeness when you come under the blood of Jesus. Let's go into Romans 6: 3 Know ye not, that so many of us as were baptized into Jesus Christ were baptized into his death? 4 Therefore we are buried with him by baptism into death: that like as Christ was raised up from the dead by the glory of the Father, even so we also should walk in newness of life. 5 For if we have been planted together in the likeness of his death, we shall be also in the likeness of his resurrection: 6 knowing this, that our old man is crucified with him, that the body of sin might be destroyed, that henceforth we should not serve sin. 7 For he that is dead is freed from sin. 8 Now if we be dead with Christ, we believe that we shall also live with him:
Also Paul says in Romans 12: 1 I beseech you therefore, brethren, by the mercies of God, that ye present your bodies a living sacrifice, holy, acceptable unto God, which is your reasonable service. 2 And be not conformed to this world: but be ye transformed by the renewing of your mind, that ye may prove what is that good, and acceptable, and perfect, will of God.