Can one lose one's salvation?

In 1 Corinthians 5:9, the topic of the church is discussed, specifically addressing the removal of two individuals engaged in sin and the prohibition of sharing meals with such a person. How can we apply the principles outlined in this text to our personal lives? Are these principles applicable beyond the church context, and if so, how can they be extended?

who is going to live on the "new earth" and "new heaven" ?

Can one lose one's salvation?