Moving platform without making it fall?

How am I able to use BodyPosition so I can make a platform (brick) move back and forth without making it fall down? I tried but it fell down instead of making it stay floated in the air. Here's the code I inserted:

local s = game.Workspace.S
local f = game.Workspace.F
local p = game.Workspace.Platform
local bp = p.BodyPosition

while true do
	bp.Position = s.Position
	wait(3)
	bp.Position = f.Position
	wait(3)
end

I'd say you should try setting the BodyPosition maxForce to something or rather if I were you I wouldn't even use BodyPosition you can just use the :lerp() method of the part which can be found here:

http://wiki.roblox.com/index.php?title=Lerp

Also if you need further help on as to how you could use the :lerp() method here I asked a question about it before and got a great answer! Here is the link:

https://scriptinghelpers.org/questions/26684/help-with-lerp-please

I hope I helped in some way or another and thank you for asking such a great question and reading my answer.

~~ KingLoneCat

My new script with :lerp() was working, but the character did not follow the brick's position... What should I do to make the character stay on the platform when it moves instead of treating it like losing a platform and fall?

Here is the NEW script:

local s = script.Parent.Parent:WaitForChild('Start')
local f = script.Parent.Parent:WaitForChild('Finish')
local p = script.Parent.Parent:WaitForChild('Platform')

while true do
	for n = 0.00, 1.00, wait() do
		p.CFrame = script.Parent.CFrame:lerp(s.CFrame, n) -- set the parts CFrame to what you got from :Lerp()
		wait(0.1)
	end
	wait(5)
	for n = 0.00, 1.00, wait() do
		p.CFrame = script.Parent.CFrame:lerp(f.CFrame, n) 
		wait(0.1)
	end
	wait(5)
end