James 4: 13 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.” 14 Why, you do not even know what will happen tomorrow. What is your life? You are a mist that appears for a little while and then vanishes. 15 Instead, you ought to say, “If it is the Lord’s will, we will live and do this or that.” 16 As it is, you boast in your arrogant schemes. All such boasting is evil.
So, does this passage tell us not to “make plans or develop a schedule for the future?” But take a look at the last verse. Do you see the problem? The person/people James was addressing were making plans based on their own wills and “schemes.”
We can certainly plan for the future but our plans need to adapt to God’s will. A bigger question may be how do we know God’s will … via much prayer and searching the scriptures.