"Behold what manner of love the Father hath bestowed upon us, that we should be called the sons of God" (1 Jn. 3:1), and so we are. O blessedness! O God's love for man! O how much God's love has accomplished! O how profusely has God's grace abounded! Poor and rejected sinners are made the children of God! The Apostle of Christ wonders at this and says, Behold what manner of love the Father hath bestowed upon us, that we should be called the sons of God, and so we are. For what is more astonishing than that a sinner should become a child of God? God's love toward man has wrought this. What is more glorious than to be called and to really be a child of God? God's grace has bestowed this on man. It is glorious to be the child of an earthly king; it is incomparably more glorious to be the child of God the Heavenly King. This honor, glory, merit, nobility, and name is more excellent than all titles of this world. For this, glory to God Who loves mankind! 
If Christians are children of God, they are also heirs, heirs, then, "of God, and joint-heirs with Christ" (Rom. 8:17). If they are children of God, what then, and whom should they fear? Why fear traitors, enemies, the devil, demons, death and hell? God shall stand up for them. "If God be for us, who can be against us?" (Rom. 8:31). We receive this most exalted gift of God in Baptism, for then we men are born of God and receive this most glorious title.
Beloved Christians! Let us remember our holy Baptism and this most exalted mercy which God then showed us: we then became children of God. Glory to God for this! But it is required of children that they should be like their parents, "That which is born of the flesh is flesh; and that which is born of the Spirit is spirit" (Jn. 3:6). Therefore Christians must be like God as they are born of God. Let us therefore show in deed that we are children of God. God is holy, let us also be holy. God is righteous, let us also be righteous. God is good, "for He maketh the sun to rise on the evil and on the good, and sendeth rain on the just and on the unjust" (Mt. 5:45); let us also be good and do good both to our friends and to our enemies, to those that love us and to those that hate us. God is compassionate, let us also be compassionate and show mercy to our unfortunate brethren. God hates sin, let us also hate every sin and turn away from it. God loves us, let us also love one another. God forgives us our transgressions when we repent, let us also forgive men their transgressions.
The Apostle of Christ admonishes us to do this: "Be ye therefore followers of God as dear children" (Eph. 5:1). When we show such character in ourselves, then we shall be true children of God and we shall receive both the inheritance and all good things promised to the children of God in Jesus Christ the Lord.
from: Journey to Heaven Counsels On the Particular Duties of Every Christian Our Father Among the Saints, Tikhon of Zadonsk, Bishop of Voronezh and Elets Jordanville, NY: Holy Trinity Monastery, 2004.
If Christians are children of God, they are also heirs, heirs, then, "of God, and joint-heirs with Christ" (Rom. 8:17). If they are children of God, what then, and whom should they fear? Why fear traitors, enemies, the devil, demons, death and hell? God shall stand up for them. "If God be for us, who can be against us?" (Rom. 8:31). We receive this most exalted gift of God in Baptism, for then we men are born of God and receive this most glorious title.
Beloved Christians! Let us remember our holy Baptism and this most exalted mercy which God then showed us: we then became children of God. Glory to God for this! But it is required of children that they should be like their parents, "That which is born of the flesh is flesh; and that which is born of the Spirit is spirit" (Jn. 3:6). Therefore Christians must be like God as they are born of God. Let us therefore show in deed that we are children of God. God is holy, let us also be holy. God is righteous, let us also be righteous. God is good, "for He maketh the sun to rise on the evil and on the good, and sendeth rain on the just and on the unjust" (Mt. 5:45); let us also be good and do good both to our friends and to our enemies, to those that love us and to those that hate us. God is compassionate, let us also be compassionate and show mercy to our unfortunate brethren. God hates sin, let us also hate every sin and turn away from it. God loves us, let us also love one another. God forgives us our transgressions when we repent, let us also forgive men their transgressions.
The Apostle of Christ admonishes us to do this: "Be ye therefore followers of God as dear children" (Eph. 5:1). When we show such character in ourselves, then we shall be true children of God and we shall receive both the inheritance and all good things promised to the children of God in Jesus Christ the Lord.
from: Journey to Heaven Counsels On the Particular Duties of Every Christian Our Father Among the Saints, Tikhon of Zadonsk, Bishop of Voronezh and Elets Jordanville, NY: Holy Trinity Monastery, 2004.