The following is an excerpt of a lesson from The Gospel Project called, "Jesus: The Faithful Son:"
Jesus' healing and exorcisms were not only proof of His authority as God's Messiah, they were also a foretaste of the future arrival of God's kingdom in its fullness when there would be no more disease and no more evil...Though there is a sense that in Jesus the kingdom is already here, until Jesus comes again, the kingdom will not yet fully arrive. Only when Jesus returns will there be no more pain, sorrow, disease, death, chaos, or evil (Rev. 21:1-4).
Ed Stetzer uses a popular illustration to describe the "already" and "not yet" nature of God's kingdom. "As World War II came to a close, there were two important dates. The first one occurred on June 6, 1944. History remembers it as 'D-day.' As a part of Operation Overload. the United States and its allies landed on the beach of Normandy, France. It was the beginning of the end of the war. Yet the war in Europe didn't end until more than a year later on May 7, 1945, also known as 'VE-day.' Despite the fact that the victory at Normandy effectively broke the back of the Axis powers, the war didn't officially end until months later. In fact, more people died between those dates than any other period of the war. It was dark and difficult, but the end had begun. It was inaugurated June 6, 1944, but the end wasn't consummated until May 7, 1945. That's the difference between D-day and VE-day. That's not a perfect parallel, but when the kingdom of God arrived in the person of Jesus, it came near, But, it will not be fully realized until Jesus returns at the end of time. The church is left to live between the times."
Until the day of Christ's return, those who have put their trust in Jesus Christ and have stopped trusting in their own works for acceptance before God live with the confident hope that we are accepted before God because of Jesus' righteousness. Even though we may still fail to obey and fall into sin, we receive God's forgiveness granted to us through Christ's obedience to God's Word.
As we await the return of Christ, the Father is placing every enemy under Jesus' feet (Eph. 1:22). After Jesus has defeated all His enemies, including death, He will deliver the kingdom to the Father, and we will enter into God's final rest, where we will finally be free from sin and disease and death (1 Cor. 15:24-28).