This is a booklet that deals with certain basic truths regarding the great change that a person undergoes as a result of believing in Jesus and accepting Him as his Lord. It is pointed out that any person who confesses Jesus as his Saviour and Lord becomes a child of God according to John 1:12. He is born of God; the spirit of God begins to dwell in him; he becomes a citizen of Heaven; God cares for him, protects him and enables him to lead a victorious life overcoming the temptations of Satan. It is the responsibility of a child of God to lead a Spirit-controlled and Spirit-filled life. He ought to live in the world, conscious of the fact that he is a child of the Holy Almighty God of Heaven. He should be perfectly just and honest in his dealings with others. All those who observe him should be able to see divine love and kindness expressed in his words and actions. He ought to spend all his money, time and energy with a view to glorifying God, imparting the message of salvation to the unsaved and doing good to all. He ought to lead a prayerful life, thanking God for the free gift of salvation and the blessings of everyday life and interceding for others. It is necessary for him to be in fellowship with the other children of God in his locality. He should be a member of the church in his place; he should attend all its meetings and do all his duties well, so that he will be an effective witness of Christ. Thus a person who becomes a child of God by believing in Christ has the opportunity as well as responsibility to attain spiritual growth and maturity. The Word of God points out that it will be a great blessing to be able to make use of this opportunity and to fulfill this responsibility, because leading a fruitful Christian life in the world ensures an unimaginably great reward before the judgment seat of Christ in Heaven. The booklet exhorts all who have become children of God to ensure that they get this blessing.