God created heaven and earth and everything in them in 6 days. He could have done it in 6 minutes or 6 seconds. Why do you think it is taking Jesus so long to prepare our Heavenly home, the New Jerusalem?
According to tradition, when a man and woman were betrothed in Biblical times, the man set about building a house on his family’s property for his future bride to share with him. The wedding didn’t take place until the house was ready. From this, some people assume that Jesus has been working all this time to prepare our eternal home and the rapture can’t take place until He is finished.
Personally, I don’t think He’s the hold up. I think the Lord could speak the New Jerusalem into existence in an instant if He wanted to. From Romans 11:25 I think the Church has a fixed number which Paul called the fullness, or full number, of the gentiles. The rapture will take place when that number is reached.