This lesson takes a lot of drawing. Stick figures work fine.
Sing: "Families Can Be Together Forever," CS, p. 188

First, you start by drawing a horizontal line on the left side of the chalkboard and draw a person standing on the line.

Sing: "I Lived in Heaven," CS, p. 4

Tell the children that we are going to learn about why we are here and how to live with our Father in Heaven again. Explain that because of the fall of Adam everybody is going to die. Draw a pit, starting from where your horizontal line left off. Write in the pit, Physical Death.

• Ask the children, 'How do we get out of the pit?' Guide them toward the answer that because Jesus Christ died for us that we will be resurrected. Make sure they know that EVERYONE will be resurrected. Explain resurrection if needed.

Sing: "To Think About Jesus," CS, p. 71

Put a picture of Jesus in the middle of the chalkboard. Draw a bridge across the pit and tell the children that to be resurrected, we don't have to do anything; Jesus did the work for us when he died for us. Draw another horizontal line extending from where the pit left off, and then draw another pit. Explain that there is another kind of death, the death of the spirit. Explain that we all are not perfect and make mistakes. Write in this pit, 'Spiritual Death.'

• Ask the children, 'How do we get out of this pit?' Explain that it isn't as easy. Explain that because Jesus Christ suffered for us in the Garden of Gethsemane, that he made it possible for us to get out of this pit. Tell them that Jesus Christ is our example. Hint: The fourth Article of Faith gives us the steps. Draw a ladder out of the pit. Ask them what they think the first step in the ladder would be. The steps are:
  Faith---sing: "Press Forward, Saints," Hymn, #81
  Repentance---sing: "Help Me, Dear Father," CS, p. 99--preferably second verse.
  Baptism---sing: "When Jesus Christ Was Baptized," CS, p. 102
  Gift of the Holy Ghost, sing "Search, Ponder, and Pray," CS, p. 109.

Explain that they need each of these things to get out of the pit. Draw a line from the picture of Christ to the bridge and to the ladder to remind them that Christ is the central figure in the Plan. Draw a horizontal line extending where the pit left off and write on the far right side, 'Eternal Life.' If needed, explain what Eternal life is. Explain that once they are out of this pit, that all is not done. We need to Endure to the End and make more covenants in the Temple before we live with our Father in Heaven again. Write 'Endure to the End.'

Conclude with testimony.
Sing: "I Am a Child of God," CS, p. 2
Help the children memorize 3 Nephi 11:33

Note: I may have to draw most of it out before on a poster board and have the children bring up word strips when I get to each point to save time.
You can change songs, of course. I used some of the songs I have here because our Primary hasn't sung some of them for a while.