And now you Gentiles have also heard the truth, the Good News that God saves you. And when you believed in Christ, he identified you as his own by giving you the Holy Spirit, whom he promised long ago. The Spirit is God’s guarantee that he will give us the inheritance he promised and that he has purchased us to be his own people. He did this so we would praise and glorify him.
Ephesians 1:13-14 NLT
http://bible.com/116/eph.1.13-14.NLT