It probably helps to know that Paul planned on going to Corinth twice but then was prevented from doing so. Some in the church in Corinth used this to say that Paul was not trustworthy, that he lied to the Corinthians. Paul tells them that he doesn’t make plans lightly, but that sometimes humans can’t do all that they want to do and plan to do. He exhorts them to not take his inability to keep his word in this instance as the inability of God to keep His word in every instance.
When God says “Yes” he means “Yes.” He keeps all His promises in Christ Jesus. His guarantee of this is the presence of the Holy Spirit in the life of a believer. We can be certain that God will keep His promises to us and so we can “stand firm in Christ.”
The Spirit’s work in us is described by Paul in amazing terms: He anointed us, set His owners seal on us, and acts as a deposit/guarantee.
What does “anoint” mean? You might look it up in a Bible dictionary or look for other places in the Bible where this word appears. What do these words tell us about the work of the Spirit in our lives? Have you found yourself doubting the promises of God lately? How does this passage address your doubts?