In the New Church the Lord Jesus Christ is recognized as the one God in His own divinely Human form, a form that He assumed with all its finite limitations and then perfected, or glorified, in the course of His 33 year battle against hell. In our view the divine Trinity is one of essential qualities - love, wisdom and use - and not one of persons, despite an appearance that way at times in the Scriptures.
Key to our understanding is that the term "Father" refers to the originating soul of Jesus, the Infinite Divine love that is beyond all human comprehension, whereas the term "Son" refers to the embodiment of that love in its working form, that is, as truth made available to the understanding in word and deed. And the Holy Spirit, far from being another personal form of God, is in fact the spirit of truth proceeding from the mouth of the Lord and giving us the wisdom we need to live a good and healthy life.
In one common concept of the Trinity, God the Father cannot abide sin, and since everyone has sinned, no one could be saved unless someone else atoned for their sins. Since no mortal could atone for all the sins of the race, all would have been lost except that Jesus, the Son of God, determined to come down into the world and take all the blame and punishment for our evils on Himself, ultimately suffering the crucifixion on our behalf. This is called the vicarious atonement, or sometimes the sacrificial atonement, reminiscent of the stories of animal sacrifice and especially the "scapegoat" in Leviticus 16. Because He was divine, so the theory goes, He could suffer infinitely, and did so in order to evoke the mercy of God towards all those who from that time forth would accept that He died for them. The Holy Spirit could then come to those who are baptized, bringing them the gifts of faith, love and grace. Although this has become the most prevalent view within Protestantism and Catholicism (although not Eastern Orthodoxy), it was unknown among the earliest Christians, and was not fully expressed until a millenium after Christ's death. (See the Wikipedia article on "substitutionary atonement" for more of the history.)
The problem with this perspective is that over and over again in the Old Testament, God says that He does forgive sin. For example, in Ezekiel God says, "I have no pleasure in the death of one who dies...Therefore turn and live!" (Ezekiel 18:32) and "If a wicked man turns from all his sins which he has committed, keeps all My statutes, and does what is lawful and right, he shall surely live" (Ezekiel 18:22). So why did Jesus have to come? Because the power of hell had become so great that people were not able to turn away from sin. And so God Himself came into the world in His own Humanity to teach and lead, and to glorify that Humanity, thereby subjugating the hells and restoring spiritual freedom everywhere. His purpose was not to offer Himself as a sacrifice, but to "bear witness to the truth" (John 18:37), and this He did out of pure love with infinite wisdom. He sacrificed Himself only in the sense that He crucified all His fleshly desires, and in doing so gained all power to put sin to death in those who follow Him. And because He rose again, He can raise us up to life by giving us a new heart, in keeping with the promise from Ezekiel 36:26: "I will give you a new heart and put a new spirit within you; I will take the heart of stone out of your flesh and give you a heart of flesh." To be saved means to live from that new heart, from the new love, rather than from the selfish loves of the old, worldly man.
Of course hardly anyone really understood what He was doing at that time and so the faith based on His work has been subject to endless arguments and church divisions ever since - the one exception until recently being a general acceptance that He rose from the dead and was seen by His disciples after the crucifixion. Now, however, through the revelation of the internal sense of the Scriptures we are in a position to understand, and we invite you to explore further by reading one of the sermons about the Lord posted in the "Other Resources" section of this website, or by reading one of Swedenborg's own books about this, for example, The Doctrine of the Lord.