The life of a believer is basically a walk of faith. Life, generally speaking, is lived on the basis of faith. The New testament draws all it's examples of faith from the lives of the Old Testament saints. Which brings us to the question of what faith is. There is no formal definition of the word faith in the Bible. What it tells us is what faith does rather than what it is.
Hebrews 11:1 - Now faith is the substance of things hoped for, the evidence of things not seen.
Without realizing it, we exercise faith everyday. Faith is therefore essential to human existence especially for believers, in their walk with God. Faith is not inherited but it is shared. In 2Timothy 1:5 Timothy's mother and grandmother shared their faith with him and he believed. As a believer, understanding faith is essential to living a successful Christian life.
Hebrews 11:6 - But without faith it is impossible to please him: for he that cometh to God must believe that he is, and that he is a rewarder of them that diligently seek him.
What the passage is simply trying to say is that to be at peace with God we need faith. There are testimonials in the scripture to show that faith plays a prominent role in receiving God's blessings. A sinner can only receive forgiveness from God if he or she repents and trust God. No one can receive blessings whatsoever from God without faith in Him.
In exercising Faith that pleases God we must be careful not to mistake faith for hope. Faith is not hope. Faith is expressed in the present tense while hope is expressed in the future. To please God through faith we must believe and act on whatever God says in His Word.