- God could give everyone enough but he make some rich and others poor.
- God could speak clearly to everyone but he gives the message to one and not to another.
- God could speak intelligibly to all, but gives a tongue to one and an interpretation to another.
In the first case so that the rich can give to the poor and learn about the grace of God in Jesus - that he too was rich but to save us became poor..... In the second so that one can share the grace they've found. In the third we learn to need one another for our growth.
If we were just individuals living "my personal relationship with Jesus" none of these things would make sense, but we're a body and he designs ways for us to learn that! A body where everyone can do everything is no use to anyone... but when we're all dependent upon each other we grow by working together... and giving credit to the one who gives all gifts and all things.