Faith is the substance of things hoped for. It is the evidence of things not seen. That is how it is described in Bible. in earthly terms, it is like you having a registered, stamp paper describing ownership of property or vehicle in your name. It is undeniable, and it is proof that the item belongs to you. It is the same in spiritual side of things. When God gives a promise of peace, protection, wisdom, supply or solution to us via his word in the scripture, it means we are allowed to claim 'ownership' of that particular thing we need.
Faith doesn't come just like that. It comes by hearing and studying the word of God. If we keep stuffing our minds with the abundance of promises offered us via the media or people who promise us this, that and the other, we are bound to find disappointment. If we believe the promises of acquiring bliss and freedom by taking loans to satisfy immediate luxuries, counting on the promise by lenders that they will help you readjust the payback, we find ourselves to be slaves to dictum of others.
On the other hand, God has proved to be trustworthy, and in spite of our own doubts and unbelief, his word and promises stand strong in our favor when we finally decide to claim them trusting God to do his part. There is this chapter 11 in the book of Hebrews that gives a brief write up on many people who took the steps of faith believing in the unseeable.
Never spend what is not yours!