Boast in the Lord

"It seems we're in a period of time when the news is getting worse everyday and we're thankful we can deliver the real good news. See with what large letters I am writing to you with my own hand. "It is those who want to make a good showing in the flesh who would force you to be circumcised, and only in order that they may not be persecuted for the cross of Christ. ... But far be it from me to boast except in the cross of our Lord Jesus Christ, by which the world has been crucified to me, and I to the world." Galatians 6:11-13 * Can someone fall away once they've come to salvation? * Does 1 John 3:9 refer to Jesus in Luke 1:35?