Thanks and praise to our Lord and Saviour Jesus Christ.
In Answers.com it says:
Confident belief in the truth, value, or trustworthiness of a person, idea, or thing.
Belief that does not rest on logical proof or material evidence. See synonyms at belief, trust.
Faith is that in which we have a belief in or trust in and cannot physically prove it. The Holy Bible tells us in Romans 10:17 "So then faith cometh by hearing, and hearing by the word of God". This tells us that faith comes from hearing, or reading, the word of God. If we believe in Jesus Christ then we are the children of God. It is that simple. We do not have to prove this to anyone. All we are commanded to do is to spread the word of God throughout the whole world and God will do the rest.
In the time of Moses , before Jesus Christ was born, the law was in effect. Answers.com tells us:
The body of principles or precepts held to express the divine will, especially as revealed in the Bible.
The first five books of the Hebrew Scriptures.
In The Holy Bible it tells us in Galatians 2:16 "Knowing that a man is not justified by the works of the law, but by the faith of Jesus Christ, even we have believed in Jesus Christ, that we might be justified by the faith of Christ, and not by the works of the law: for by the works of the law shall no flesh be justified".
To be justified is to be taken from sin to the state of God's grace. Grace is the undeserving love of God for man. This is not achieved by the works of any kind by man but through the faith of Jesus Christ.
In the Gospel of John one verse sums it up. John 3:16 "For God so loved the world, that he gave his only begotten Son, that whosoever believeth in him should not perish, but have everlasting life".
God's only begotten son, Jesus Christ, is the only way to the Father. Hebrews 12:2 "Looking unto Jesus the author and finisher of our faith; who for the joy that was set before him endured the cross, despising the shame, and is set down at the right hand of the throne of God". You see the author and finisher of our faith is Jesus Christ. Where in Matthew it tells us in chapter 22:37 "Jesus said unto him, Thou shalt love the Lord thy God with all thy heart, and with all thy soul, and with all thy mind. 38: This is the first and great commandment".
I will finish with Galatians and in it you can read that it is telling us again that we are the children of God through our faith in Jesus Christ and not being under the law.
Galatians 3:22-29 22: But the scripture hath concluded all under sin, that the promise by faith of Jesus Christ might be given to them that believe. 23: But before faith came, we were kept under the law, shut up unto the faith which should afterwards be revealed. 24: Wherefore the law was our schoolmaster to bring us unto Christ, that we might be justified by faith. 25: But after that faith is come, we are no longer under a schoolmaster. 26: For ye are all the children of God by faith in Christ Jesus. 27: For as many of you as have been baptized into Christ have put on Christ. 28: There is neither Jew nor Greek, there is neither bond nor free, there is neither male nor female: for ye are all one in Christ Jesus. 29: And if ye be Christ's, then are ye Abraham's seed, and heirs according to the promise.