Most people who I run into say that it is not, so I have a challenge(not being combative) for those who believe that we cannot discern the difference between a saved person and a lost person : Produce a verse or verses that you think states that we cannot know if someone is saved. (I will be open to the rebuke of Scripture. Besides the wheat and the tares, I have not found any verse that suggests this.) For those who are undecided on this issue, here are some verses that say we can judge someones salvation by the lifestyle that they live: Matthew 7:13-20, Ephesians 5:5, Galatians 5:19-21, and many verses in 1 John. 1 John 2:3,4 is a good one, but many more.