1 Timothy 4:16 (NKJV)
The term "ripple effect" is used to describe how one thing can have an influence on several other things. For example, when you buy something in a store, you can then use what you bought. Once you have made your purchase, the store needs to order something to replace what was sold, the company that made the product now needs to make a replacement for the item that you bought, and so on. We do not always realize it, but one thing we do can have an effect on many other things.
Paul told Timothy in 1 Timothy 4:16 that Timothy should pay attention to himself and his doctrine (teaching). The reason Paul gave for this was that if Timothy would be sure to take care of himself, and if he would be sure to have correct doctrine, Timothy would save both himself and those who heard him. The things Timothy did would affect his own life and the lives of those around him. This same thing is true for all of us, what we do can make a difference in our own lives and in the lives of others.
Most of the time, we think about our lives and what God is directing us to do in relation to how these things will affect us. As Paul told Timothy, what we do for ourselves and the things we teach, the things we believe, will have an impact on others. We think about the plan and purpose God has for our lives and how it will effect us, but God sees the ripple effect of how our obedience to His plan and purpose will benefit others. We all need to realize that what we do, and what we believe, can be a major influence for good in the lives of others.