Baptism works from the outside in

For it is of the greatest importance that we esteem Baptism excellent, glorious, and exalted, for which we contend and fight chiefly, because the world is now so full of sects clamoring that Baptism is an external thing, and that external things are of no benefit. But let it be ever so much an external thing, here stand God’s Word and command which institute, establish, and confirm Baptism. But what God institutes and commands cannot be a vain, but must be a most precious thing, though in appearance it were of less value than a straw.