Eph. 3:11 tells us that God has an eternal purpose. Just pause there a moment to think about that word purpose. It's not a wish or a hope, it's not something that God would like to see happen if at all possible. No, it's the eternal purpose of our sovereign God.
When we make plans they depend on many things around us. They may depend on circumstances or on other people. They may depend on the economy or the weather. They may depend on our strength or intelligence. They also depend on us. That means that some of our best laid plans come to nothing. Much as we would sometimes like something to happen, it isn't always possible for there are reasons beyond our control. There are no reasons, however, beyond God's control. There is no one upon whom and nothing upon which God is dependent. He is the sovereign Lord who controls the whole of creation, and so nothing can get in the way of His plan. God's plan is not like our plans because God is not like us; He is the all-powerful and all-sufficient One.
That means that we can have confidence that God's purpose will come to pass. No matter how discouraging the circumstances around us may be at times, God's purpose will come to pass. When we see little fruit from evangelistic efforts we can take comfort in the fact that God's purpose will come to pass. If things are discouraging at church we are reassured by the fact that God's purpose will come to pass. If all we can see are obstacles and difficulties in our lives, we can look ahead with confidence for we know that God's purpose will come to pass.
God's purpose will certainly come to pass, for it is not a nice thought, a wish or desire, but rather the eternal purpose of the eternal God.