Hebrews 11:1 (NKJV)
Faith is an important part of the Christian life. We are saved through faith (Ephesians 2:8), we live by faith (Galatians 3:11), and without faith it is impossible to please God (Hebrews 11:6). From these verses we can see that faith is important, but what is faith and how does it work? If we are saved through it, we live by it, and faith pleases God then we need to know what faith is and how to use our faith. Faith is just taking what the Bible says, accepting it, and acting like it is true; we act and speak about a situation based on what the Bible says about it, that is faith.
Faith means that we put our trust, focus, and confidence in what God has said in His Word. We don't trust in our own abilities, we don't focus on our circumstances, and we don't put our confidence in natural things. When we are in faith about something we will be at peace and rest in our hearts even if we still have questions in our head. We can put our trust and confidence in what God has said in His Word while still not completely knowing or understanding exactly how God will do what He said He would do, that is faith.
When we are in faith about something we are really just saying that we know God will help us with what it is that we need and everything is not just left up to us. God may give us an idea about something we can do in the situation but that does not mean we are trying to do it on our own, our focus is on what God has said not on what we can do. Faith is not based on our actions but our actions must be in agreement with what the Bible says. Faith is not a mystery, faith is believing what God says and then acting on that and saying that, that is faith.