Joshua 1:7-8
7 Only be strong and very courageous; be careful to do [everything] in accordance with the entire law which Moses My servant commanded you; do not turn from it to the right or to the left, so that you may prosper and be successful wherever you go. 8 This Book of the Law shall not depart from your mouth, but you shall read [and meditate on] it day and night, so that you may be careful to do [everything] in accordance with all that is written in it; for then you will make your way prosperous, and then you will be [d]successful.
What is the foundation and basis of your courage? If it is not in the word of God then it is built on the wrong foundation. The word of God is truth which cannot be shaken. God tells Joshua to be strong and courageous but he stresses the importance of the word and walking according to it without compromise. The word is so important and foundational that God tells him that it should be all that Joshua thinks and talks about day and night, it should be all he that he does and if he follows this process then he shall make his way prosperous and successful.
Romans 10:17 (AMP)
17 So faith comes from hearing [what is told], and what is heard comes by the [preaching of the] message concerning Christ.
Just as with Joshua, our faith and courage are activated when we hear the word then we have the confidence to go out and do as it says because we have the understanding that God is not a man that He should lie and what He has spoken He will make good.
I believe the key to living as a courageous believer is to soak your mind in the word day and night. Like Joshua you have to declare it, meditate upon it day and night and be careful to do what it says no matter what the situation is in the natural. There is a confidence and a boldness that we can only get when we know what God is saying about us and our situation and can only happen when we soak ourselves in the word.
Do you want to make your way successful and do you want to be prosperous in all your ways? The formula is right there; This Book of the Law shall not depart from your mouth, but you shall read [and meditate on] it day and night, so that you may be careful to do [everything] in accordance with all that is written in it; for then you will make your way prosperous, and then you will be successful.