I suppose that you are trying to prove you can lose your salvation because you have seen something that to you proved this was true. Is this the case?

As others have already stated, Christians are the ones who bear fruit for Christ.
John 15:15:2 Every branch in Me that does not bear fruit He takes away; and every branch that bears fruit He prunes, that it may bear more fruit.

Some people will claim to be Christians, but the Lord will say he never knew them. He doesn't say he used to know them and then they were lost, he says he never knew them.

The Holy Spirit was given to believers to abide with them forever.
John 14:16 And I will pray the Father, and He will give you another Helper, that He may abide with you [color:red]forever--
That was Jesus' promise to his disciples and to all Christians. If they do not have the Holy Spirit, they are not His. He promises the Holy Spirit will be with them forever.

1 John 2:19 They went out from us, but they were not of us; for[color:red] if they had been of us, they would have continued with us; but they went out that they might be made manifest, that[color:red] none of them were of us.

I am thinking that your problems are because of your definition of a Christian.
Jesus promises he will never leave us or forsake us. He has the power to keep us safe to the end.

Josh, I believe that you need to look at more than one verse to see what the Bible is really saying about this issue.
What kind of Savior can you offer people if He is unable to keep you till the end?
Isaiah 49:15
"Can a woman forget her nursing child, And not have compassion on the son of her womb? Surely they may forget, Yet I will not forget you.
See, I have inscribed you on the palms of My hands; Your walls are continually before Me.

I have seen an elderly lady who became a Christian about the same time as I did who later was afflicted with alzheimers. How wonderful to know that she was safe in the Lord's hand even when she didn't know her own family!