1 Pt 1:2, Rev 7:14, Col 1:20, Rom 3:25, Rom 5:10, 2 Cor 5:18-19, Eph 2:16, Col 1:22, 1 Jn 2:2, 1 Jn 4:10
In the Old Testament, God had the Israelites slaughter a ram to offer it as a peace offering to God. (Ex 29:15-18)
Ex 29:15 Thou shalt also take one ram; and Aaron and his sons shall put their hands upon the head of the ram. 16 And thou shalt slay the ram, and thou shalt take his blood, and sprinkle it round about upon the altar. 17 And thou shalt cut the ram in pieces, and wash the inwards of him, and his legs, and put them unto his pieces, and unto his head. 18 And thou shalt burn the whole ram upon the altar: it is a burnt offering unto the Lord: it is a sweet savour, an offering made by fire unto the Lord.
God made Jesus the propitiation sacrifice to forgive our sins and to be reconciled to us. (Romans 3:25, Romans 5:10, Ephesians 2:16, Col 1:22, 1 John 2:2, 1 John 4:10)
Romans 3:25 Whom God hath set forth to be a propitiation through faith in his blood, to declare his righteousness for the remission of sins that are past, through the forbearance of God;
Romans 5:10 For if, when we were enemies, we were reconciled to God by the death of his Son, much more, being reconciled, we shall be saved by his life.
Ephesians 2:16 And that he might reconcile both unto God in one body by the cross, having slain the enmity thereby:
Col 1:22 In the body of his flesh through death, to present you holy and unblameable and unreproveable in his sight:
1 John 2:2 And he is the propitiation for our sins: and not for ours only, but also for the sins of the whole world.
1 John 4:10 Herein is love, not that we loved God, but that he loved us, and sent his Son to be the propitiation for our sins.
Also, because Jesus died on the cross, all things were reconciled to God. (Col 1:20)
Col 1:20 And, having made peace through the blood of his cross, by him to reconcile all things unto himself; by him, I say, whether they be things in earth, or things in heaven.
And since we have been reconciled to God through Christ, we have the office of reconciling people to God. In other words, you can reconcile people to God by preaching Jesus as the Christ. (2 Corinthians 5:18-19)
2 Corinthians 5:18 And all things are of God, who hath reconciled us to himself by Jesus Christ, and hath given to us the ministry of reconciliation; 19 To wit, that God was in Christ, reconciling the world unto himself, not imputing their trespasses unto them; and hath committed unto us the word of reconciliation.