At this time, when a child of God dies, their immaterial side (their soul and spirit) goes to be with the Lord in heaven.  (2 Corinthians 5:8)   At a future date, they will be resurrected from the grave, given glorified bodies,  and taken back to heaven.  This event is known as the rapture of the Christian Church.  (1 Thessalonians 4:13-17; 1Corinthians 15)  Christians who are alive at the time of the rapture will, also, be taken to heaven.  Both will be there for seven years before returning to earth.

At the end of the seven year period, they, Christ Jesus, and the holy angels will return. (Revelation 19:11-19)   This is known as the second coming of the Lord.  It's, also, when the battle of Armageddon will take place.