2 Cor 1:19-22
For the Son of God, Jesus Christ, who was proclaimed to you by us, Silvanus and Timothy and me, was not "yes" and "no," but "yes" has been in him. For however many are the promises of God, their Yes is in him; therefore, the Amen from us also goes through him to God for glory. But the one who gives us security with you in Christ and who anointed us is God; he has also put his seal upon us and given the Spirit in our hearts as a first installment.
