Scriptures points to the saving death of Christ for them He died for. Now all for whom He died had a legal union with Him and were in Him, so that when He died, they died with Him just as they had a legal union with Adam so that when he died, they died with him. So for those in Christ when He died for them, and rose again, so too also they having died in Him, must also be raised up in newness of life Rom 6:4-6
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.
See those Christ died for shall walk in the newness of life, will be delivered from being a servant of sin, which is unbelief. In other words they for whom Christ died will be born again, partake of the renewing of the Holy Ghost Titus 3:5
5 Not by works of righteousness which we have done, but according to his mercy he saved us, by the washing of regeneration, and renewing of the Holy Ghost;
The renewing of the Holy Ghost equates to walk in the newness of life in Rom 6:4 above.