"Many are the plans in a man's heart, but it is the Lord's purpose that prevails." Proverbs 19:21 (NIV)
"If it is the Lord's will, we will live and do this or that. (James 4:15 NIV) "
Have you noticed that things don't always turn out the way you want them to? That sometimes God has a better idea?
The Bible says in Proverbs 27:1, "Don't boast about tomorrow. You don't know what tomorrow's going to bring." (ESV)
It's okay to make your plans, but remember that life is unpredictable and God says we shouldn't presume on it. On the other hand, we shouldn't worry about it because God is in control.
James 4 tells us the proper attitude to have: "Now listen you who say 'Today or tomorrow we will go to this or that city, spend a year there, carry on business, and make money.' Why, you don't even know what will happen tomorrow. ... Instead, you ought to say, 'If it is the Lord's will, we will live and do this or that.'" (vv. 13-15, NIV)
James is saying it's OK to make plans, but just realize that ultimately God has the final word.
The right attitude is to always keep your plans submitted to God. Make your plans but say, "God, if this is what You want, this is the direction I'm going to go. I'm doing this with flexible faith."
Proverbs 16:9 says, "We should make our plans counting on God to direct us." How do you do that? By praying. When you get up in the morning and have your quiet time, say, "God, what do You want to do with this day?"
Then when interruptions come, you'll remember God is in control. It will dramatically lower the frustration level in your life as you remember it is not all up to you.