Sometimes we get so busy doing the 'tasks' that we think God has instructed us to do that we can miss the purpose for which He has called us.
Jesus tells a story of people being invited to a great banquet. the servants are sent out several times, but the task of inviting is not the point. As the Master says, "Compel them to come in, so that my house will be full."
We are not called to just make invitations - God desires a FULL HOUSE!