Wrong.
That's an excuse that the church has adopted from the world.
God can do just as much with your last drop as He can when you're full.
Ask yourself why you keep checking the bucket in the first place...
Your job is to serve, and be in His Word.
God is in charge of the bucket, and the only One who can replenish it (which He does primarily through His Word.)
He will give you what you need to serve Him.
You just keep serving Him.
