All of us are tested in our faith and every one of us has the ability to overcome the test. There are things in life that will require you to prove your faith. Like in the case of Abraham, his faith was tested when God asked him to sacrifice his only son and Abraham never withheld his son from God. When he was about to kill him in sacrifice, God said to him:
“Do not lay your hands on the boy or do anything to him, because now I know that you fear God, seeing you have not withheld your only son from Me.” (Genesis 22:12)
If you say you believe but you do not act your faith in the time you have to show that you believe, then you have failed the test. How do you show faith? You show it when you obey and practice what is written.
"As the body without the spirit is dead, so faith without works is dead.”(James 2:26)
There is a time to believe and a time to manifest your faith. Faith without being tested cannot be approved. As the above verse clearly states that “faith without works is dead”.
When you do what God want you to do, then you are showing that you truly believe in God. Even the earthly institutions like universities test you to qualify you as a professional. How much more will the approval to qualify you for salvation be? If you want to obtain the promises of God, then your faith has to be approved. God is merciful but He requires that you act out your faith to show that you truly love and believe Him.