Can I lose my salvation?

No. The believer is eternally secure. When Paul tells the Corinthians “you are saved,” the verb is present tense — you are saved now, and you are going to be saved tomorrow, next year, and forever (1 Cor. 15:2). When he says they “stand,” the perfect tense means they took their stand on Christ at a point in time with the result that they will stand forever. You did not save yourself — salvation is received, not achieved — so you cannot un-save yourself; it rests on the finished work of Christ, not on your performance. Salvation is the once-for-all victory. And passages sometimes used to deny eternal security, such as believing “in vain,” do not mean a believer can fall away; in context Paul is answering those who doubted the resurrection itself, not warning the saved.