Our destinies are promised and set up for us, however its our choice if we will get to them.
Let me paint the picture for you... God had already said that the Land of Canaan was the Israelite's It was for them to trust God to get them to the land. Instead, they complained and doubted because of the many oppositions they had to endure. Then when they got to spy on the land they became scared of the who had already possessed the land. Forgetting that God had promised the land to them.
Abraham was promised to be a father of many nations. He at one point thought it was taking to long. So his wife Sarah offered her handmaiden to produce a child. Yeah well that wasn't God's plan at all. However Abraham choose to believe God would do what He said. And finally Sarah gave birth to Issac who gave birth to Jacob and so forth..... Abraham walked into His destiny
So again our destiny is established already by God. Rather or not we get to walk into it is our choice. Choose to hold on to every word God says concerning your future. It will not be an easy road, and we may wait years before it materialize. We may even fall into temptation but never stop trusting God. He is faithful to do just what He said He would...