Youcat commented through CCC. Question n. 2.

YOUCAT Question n. 2 - Why did God create us?

(Youcat answer) God created us out of free and unselfish love.  

A deepening through CCC

(CCC 3) Those who with God's help have welcomed Christ's call and freely responded to it are urged on by love of Christ to proclaim the Good News everywhere in the world. This treasure, received from the apostles, has been faithfully guarded by their successors. All Christ's faithful are called to hand it on from generation to generation, by professing the faith, by living it in fraternal sharing, and by celebrating it in liturgy and prayer (Acts 2:42).

Reflecting and meditating 

(Youcat comment) When a man loves, his heart overflows. He would like to share his joy with others. He gets this from his Creator. Although God is a mystery, we can still think about him in a human way and say: Out of the “surplus” of his love he created us. He wanted to share his endless joy with us, who are creatures of his love.

(CCC Comment)

(CCC 2) So that this call should resound throughout the world, Christ sent forth the apostles he had chosen, commissioning them to proclaim the gospel: "Go therefore and make disciples of all nations, baptizing them in the name of the Father and of the Son and of the Holy Spirit, teaching them to observe all that I have commanded you; and lo, I am with you always, to the close of the age." (Mt 28:19-20) Strengthened by this mission, the apostles "went forth and preached everywhere, while the Lord worked with them and confirmed the message by the signs that attended it." (Mk 16:20). (CCC 358) God created everything for man (Cf. GS 12 § 1; 24 § 3; 39 § 1),  but man in turn was created to serve and love God and to offer all creation back to him: What is it that is about to be created, that enjoys such honour? It is man that great and wonderful living creature, more precious in the eyes of God than all other creatures! For him the heavens and the earth, the sea and all the rest of creation exist. God attached so much importance to his salvation that he did not spare his own Son for the sake of man. Nor does he ever cease to work, trying every possible means, until he has raised man up to himself and made him sit at his right hand (St. John Chrysostom, In Gen. sermo II, 1: PG 54, 587D-588A).  

(The next question is:  Why do we seek God?)