Your question really made me laugh! I think the balance between “selling yourself” and being “humble, generous, and loving” is actually nailed in your last phrase: be the person God’s calling you to be. The nice part about resting in how you were created is that you actually don’t have to sell yourself. People can tell very quickly when they meet you what type of a person you are. Are you eager, quick, thoughtful, serious, enthusiastic, motivated, experienced, critical, mean, competitive, ambitious, a leader, funny, nervous, confident, reasonable, able to share blame and/or success, optimistic, impatient? It won’t be easy to hide. Think about the movers and shakers in your field. When you meet them in person, do they match what you know of them from their work? We all know amazing experts who are horrible, mean, narcissistic, or dismissive in person. I bet you also know people who are even better in person than you would have guessed, who are interested in you and actually care about what you do or helping you in your work.
It’s worth taking the time to prepare a brief pitch summarizing who you are, what you do, and what you’re looking for, if you are on the job hunt or trying to meet collaborators. But the bottom line is that your work is your strongest advertisement. I’d put more effort into doing your work and getting it published than on trying to “sell yourself” to potential colleagues. And ultimately, if God has called you to do this work, be confident that he will open the doors you need, which might include “serendipitous” meetings with those movers and shakers in line at a conference buffet, or in an elevator. Don’t be shy about introducing yourself if you recognize someone you admire, and complimenting their work or explaining how they’ve contributed to your interests or ideas. That’s not selling yourself; it’s being honest. If you have to make it up, or “butter them up,” don’t do it.
Jesus met important, influential people (Nicodemus and Zacchaeus come to mind) and was able to sell them on himself and the gospel while still being humble. I believe the key, as you mention in your question, is “loving.” Jesus considered the needs and issues of others, and he was able to help many of them grow. Jesus also did exactly the same thing with unimportant people (fishermen, beggars, lepers, etc.). So, if you have skills, traits, or knowledge that might be able to help others (both people who are important in your field and people who are not recognized), offer your assistance! Personally, I find that a sincere and competent offer to help always makes a good impression on me.
My main recommendation would be to avoid over-promotion. Whether you’re writing an application, meeting at a conference, or in an interview.
Some specific things to watch out for:
Inflating your accomplishments
Don’t inflate your accomplishments, even for hobbies. For example, one search committee I was on interviewed a candidate who kept talking about some creative writing she had had published. It turned out to be self-published. While there is nothing wrong with self-publishing, she had not described her work that way at all. The accomplishment was actually unrelated to her professional life and she should have simply avoided mentioning it, or simply claimed to do some creative writing on the side.
Ignoring people in the process
Sometimes a candidate is very gracious and interested, but only in the company of some of the people they encounter. Make sure you enquire about the other people you are meeting as well. Knowing what others have done and being able to connect with them will keep you from over-promoting yourself.
Failing to be a team member
If you come across as if your own career is the only thing you are interested in, you will be seen as arrogant. However, if you do not express a drive to succeed, you will be seen as weak and unlikely to do well. The expectations vary by workplace. Know what type of person is needed for the job. If you are interested in a small, teaching institution, a willingness to share space and equipment is a must, finding research that can be done with undergrads is important, and showing that you are willing to meet needs in the institution is important. Don’t scorn teaching non-majors if that is part of the job. However, don’t express a willingness to agree to anything, just anything at all, to get a job. They want to hire you for your skills. Make sure they know you have them.
Presenting an overly casual style
An overly casual appearance or approach is sometimes interpreted as arrogant. If others are in jackets and ties or blouses and skirts and you are untucked and look disheveled, or are very informal in your speech, people might assume, “She is just comfortable in her own skin.” However, they also might assume, “She thinks too much of herself and is immature and arrogant.” If necessary, check with others who have been to the conference you’re going to or know the institution you will be visiting to give you some sense of the level of formality.
My best advice would be to look for a workplace that is looking for you. If you are convinced you are a good fit for that job, make that case. To do so is not pride. Look at yourself from the outside. Are you really a good match? Will you meet the needs that have prompted them to hire someone? If you think so, go for it. Be respectful, accurate, interested in the good of the people hiring as well as yourself, and you will do fine.
Dorothy covered most of what I was thinking — I, too, was mainly going to caution against over-promotion.
The thing I would stress in job searches or in networking at conferences is to be prepared to discuss colleagues’ work. Spend time getting familiar with the work of the individuals you might encounter, so that you can ask questions no matter how simple or naive. Most professors really enjoy talking with a student — or potential colleague — who is interested in their work.