avid spoke of himself saying that he was “set in his ways” ...but he was speaking positively, not negatively. "My heart is fixed," he declared (Psalm 57:7). He was stating that his mind was made up. His intentions sure. His purpose settled. He had decided that he was going to praise God, no matter what.
Now, it’s one thing to make such claims when things are going well, but David did so while hiding in a cave; hiding from King Saul. He declared his certainty concerning his direction while he was in the midst of calamity (Psalm 57:1). He felt like his enemies were fiery monsters with spears for teeth and swords for tongues (Psalm 57:4). His enemies were like lions to him. They were so bent on his destruction that they were willing to risk their own heads to try to remove his (Psalm 57:6). And yet, David was sure that God would take care of him (Psalm 57:3). So, he purposed to praise God as he benefited from His performance (Psalm 57:2 & Philippians 1:6). His plan was set... and a good plan it was too.
Here is something to consider though. Fulfilling our good intentions can be an incredibly difficult thing to do in life. Primarily due to our ignorance about the future and due to our own depravity, falling short of our goals is very common. It would be wise for us all to seek for God's energy and empowerment in order to live up to the noble futures that our desires portend. Without His aid, the best of intentions are doomed and our good momentum becomes meaningless. We all need Him (Philippians 2:13, Proverbs 16:9 & 33).