based on the LGG Study, Secure in Christ, w1d4
Read:Ephesians 1:11-14; SOAP: verse 13
And when you heard the word of truth (the gospel of your salvation)—when you believed in Christ—you were marked with the seal of the promised Holy Spirit,
Ephesians 1:13
What a joy to know that because we have placed our faith in Jesus Christ we have been marked with the seal of the Holy Spirit. Being marked by the Holy Spirit is the assurance that we belong to God. He has identified us as His own and we are secure in Christ. No one and nothing can change it or take the promised inheritance away.
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 1:14
The added bonus is that we aren’t just marked by the Holy Spirit, instead He is sent to live within every believer. However, He isn’t a silent partner of the trinity, rather He works on God’s behalf to “convict, guide, renew, unite, and encourage us daily.” He produces in us evidence, like love, grace, mercy, and peace, patience, kindness, goodness, faithfulness, and self-control – so that others know that we belong to Him. When this happens God receives glory, honor, and praise.
Me From the Inside Out 