14 What good is it, my brothers, if someone says he has faith but does not have works? Can that faith save him? 15 If a brother or sister is poorly clothed and lacking in daily food,16 and one of you says to them, “Go in peace, be warmed and filled,” without giving them the things needed for the body, what good is that? 17 So also faith by itself, if it does not have works, is dead.
18 But someone will say, “You have faith and I have works.” Show me your faith apart from your works, and I will show you my faith by my works. 19 You believe that God is one; you do well. Even the demons believe—and shudder! 20 Do you want to be shown, you foolish person, that faith apart from works is useless? 21 Was not Abraham our father justified by works when he offered up his son Isaac on the altar? 22 You see that faith was active along with his works, and faith was completed by his works; 23 and the Scripture was fulfilled that says, “Abraham believed God, and it was counted to him as righteousness”—and he was called a friend of God. 24 You see that a person is justified by works and not by faith alone. 25 And in the same way was not also Rahab the prostitute justified by works when she received the messengers and sent them out by another way? 26 For as the body apart from the spirit is dead, so also faith apart from works is dead. 
How do you know, that you have faith? It must show somewhere. And the way it shows, is simple. Mat. 15:18-19 says
18 But what comes out of the mouth proceeds from the heart, and this defiles a person.19 For out of the heart come evil thoughts, murder, adultery, sexual immorality, theft, false witness, slander.
All these things are works that come from your heart. If your heart in such a way, that you have these things, then you don`t know the Father. 1. John 2:4, 9 says:
God does not know lies, and he is light, as 1. John 4:8 says, so, if you have evil thoughts, like hate, or anything else from the list, or similar things. You do not know God. You say, that you believe in God? The scripture says – that is good, also demons believe that, and shake from him in fear. So, it is not a real sign. The real sign are your works. John 14:15 says, if you love me, you will keep my commandments. God`s commandments, put in one sentence is – Love God from all your heart, mind, strength and soul, and love your neighbor. That is what God asks of you. As we have seen, they are related together.
How do you show your love? Again, with works. Works speak louder than words. Be practical about it. That will show everyone, whom you belong to, and it will be a witness to God`s nature of changing people`s lives.
 The Holy Bible: English Standard Version. (2001). (Jas 2:14–26). Wheaton: Standard Bible Society.
 The Holy Bible: English Standard Version. (2001). (Mt 15:18–19). Wheaton: Standard Bible Society.
 The Holy Bible: English Standard Version. (2001). (1 Jn 2:4). Wheaton: Standard Bible Society.
 The Holy Bible: English Standard Version. (2001). (1 Jn 2:9). Wheaton: Standard Bible Society.