What do you think of a guy who says things like the following?
"I wanted to come to you first, so that you might have a second experience of grace" (2 Corinthians 1:15).
"I know that I will … continue with you all for your progress and joy in the faith, so that through my being with you again your joy in Christ will overflow on account of me" (Philippians 1:25-26).
"Perhaps I will stay with you a while, or even spend the winter, so that you can help me on my journey, wherever I go" (1 Corinthians 16:6).
You and I are used to Paul-to the point of inured. But what if someone you know talked like that? Would you think to yourself, "Well, you sure think a lot of yourself"? Or, "What makes you think that being with you is an 'experience of grace'? Do you think you're Jesus?" Or, "You have a lot of nerve assuming we even want you here for the winter, and assuming we want to help you on your journey! We didn't even invite you!"
I have noticed that the far side of humility looks like pride. The people who are the closest to being truly humble are wont to say things like what Paul says in these cited examples. They are so far above the "games" we play, as we trying to look humble, that an unspiritual person might mistake their way of speaking as insensitivity or arrogance or lack of love.
Here is the irony: The way Paul speaks is exactly the way Love would speak. Think about it: It is only if I believed the highest things about you ("Love … believes all things," 1 Corinthians 13:7) that I would dare to assume that you would want me to spend the winter with you, and to help me on my journey. It is only if I give you the benefit of the doubt that our love is mutual, and that you acknowledge Christ's work in me, that I would assume you are grateful for the grace you experience whenever I visit (2 Corinthians 1:15-16). It is only if I think highly enough of your character that I expect you to show hospitality with simplicity of heart for the sake of Christ. Because I love and esteem you, I am assuming that you don't have worldly ways of reacting.
Humility is acknowledging reality. Humility does not put on airs of self-deprecation. Humility calls a spade a spade: "I am the chief of sinners" (1 Timothy 1:15), in the sense that I was not only an unbeliever but also a persecutor of the Church. But also, "By the grace of God I am what I am. … I worked harder than any of them" (1 Corinthians 15:10).
No brag. And none of the self-deprecation that is inverted pride. Just the truth before God. And assuming the best of your heart.