The future depends on what you do today.
Context
Mahatma Gandhi condenses the principle of cause and effect into a simple, powerful statement. The "future" is not a predetermined event that happens to us; it is a consequence that is actively built by the choices and actions we take in the present moment.
This quote places the agency for our destiny squarely in our own hands. What you learn today, the habits you form today, the relationships you nurture today—these are the bricks with which you are constructing your tomorrow. There is no separate future; there is only a long series of "todays" that eventually arrive.
This is a call to present-moment responsibility. It reminds us that there is no time to wait for the perfect moment to begin. The most powerful thing you can do for your future is to take purposeful, positive action right now.