Substitution: the Law of God required the death of the sinner, “The soul who sins is the one who will die.” ; and God’s love for mankind had to find another way of satisfying this demand, and from the very outset of the fall of mankind God instituted what the Scriptures reveal as a substitution to satisfy this demand, “The Lord God made garments of skin for Adam and his wife and clothed them.”, and these garments had to come from an animal that was killed, which in effect took their place in death, and they were clothed in the righteousness of God through Christ Jesus our Saviour, symbolized in all the animal sacrifices of the Old Testament . All these sacrifices; as outlined in Exodus, Leviticus, Deuteronomy and elsewhere in the Old Testament, had to be acceptable to God, and equivalent to the condemned person, and in the case of Christ, innocent, willing to die, and possessing an infinite life, so as to satisfy God’s Law which demanded a life for a life . So it is obvious that these requirements could only be satisfied by our Lord Jesus Christ . Redemption: the root meaning is to buy or to buy back again; and refers to a liberation from sin and its oppression; and is illustrated in the Old Testament as a relative called a “kinsman redeemer” who had the right to buy back property that had been sold by a family member due to debt, poverty or sickness, so as to keep it in the family . Although the completed work of Christ is adequate in providing salvation for all mankind, it can only be effective to those that accept and believe in Him, and His work of redemption is expressed in different ways throughout the New Testament . As has been shown in our previous study of sin, mankind belongs to God because of our nature or characteristics, but because of sin we have come under the control and oppression of Satan, and through redemption Christ has secured the release of our souls. Propitiation: meaning satisfaction, which is also an aspect of Christ’s completed work, for He was the “atoning” sacrifice or the “substitutionary atonement” (NIV Study Bible) for our sins . Reconciliation: and in this we see that mankind is reconciled (or meets the requirements) to God, and simply means a complete change of our attitude towards God . Christ’s completed work provided reconciliation for all mankind meaning that all mankind can be saved , but again we must understand that this does not mean that all mankind is, or will be saved for we are all called upon to “Be reconciled to God” , even as all things in heaven are reconciled
The work of the Holy Spirit is to convict mankind of sin, righteousness and judgment: “When he comes, he will convict the world of guilt in regard to sin and righteousness and judgment: in regard to sin, because men do not believe in me; in regard to righteousness, because I am going to the Father, where you can see me no longer; and in regard to judgment, because the prince of this world now stands condemned.” . If it were not for The work of the Holy Spirit in the lives of mankind, no one would be saved, because of the sin nature we are all dead in our sins and spiritually blinded by Satan , and in our natural sinful state we do not accept the things relating to God, nor do we seek God . Christians can assist in the work of the Holy Spirit by the lives that we live, so we should not frustrate His work.