My script won't work. How do I make one text switch to another text?

local screen, text = Instance.new('ScreenGui'), Instance.new('TextLabel')

screen.Parent = game.StarterGui
text.Parent = screen

text.Text = 'A player just spawned and did not know what just happened.'
text.Position = UDim2.new(0, 360, 0, 450)
text.Size = UDim2.new(0, 0, 0, 0)
text.Font = 'SourceSans'
text.FontSize = 'Size24'
text.TextColor3 = Color3.new(255 ,255 ,255)
gui = script.Parent
wait(5)
gui:Destroy()

text.Text = 'What could the player possibly do?'
text.Position = UDim2.new(0, 360, 0, 450)
text.Size = UDim2.new(0, 0, 0, 0)
text.Font = 'SourceSans'
text.FontSize = 'Size24'
text.TextColor3 = Color3.new(255 ,255 ,255)