Around 300AD, Constantine received the vision that would carry him through. According to history, the symbol of the Cross appeared in the sun accompanied by the Latin words "In hoc signo vinces". It meant "In this sign, you will conquer". ...
In this sign
The Cross is indeed the most supercharged symbol the world over. I suppose the condesity of said symbol, in the minds and hearts of onlookers, would necessarily be commensurate with the understanding of what it means. I'm being pedantic. Just because someone uses or wears or assents to the Cross doesn't mean they know the Person who died on it. Granted, lots of conquering was done by Constantine in the name of Christ but he didn't actually accept Him as saviour until his deathbed. Contrast that with his successor (thrice removed) Julian the Apostate who was brought up in the rudiments of Christianity only to reinstate Paganism upon taking the throne. Julian took a handful of his blood as he lay dying on the battlefield and threw it at the sky, declaring Christ the victor. Perhaps he made peace with the Lord at that moment?
In this style
It's easy to succinctly synopsize a life with soundbites. Harder though, to pass judgment. In some mood, one might consider Julian's life of atheistic unbelief and subsequent acquiescence to Jesus a model of deathbed repentance while the opposite could be said of Constantine. Where in the Bible does Jesus ever talk about conquest and spoil? Only to have it be revealed after the fact to Constantine in a vision and then galvanized with a dream (it's said that Christ appeared to Constantine in a dream substantiating the vision in the sun). Is what Constantine enacted, i.e. the governmental sanction of Christianity, any better or worse than Julian's attempt at the opposite? I imagine everyone stepping foot in Heaven will be surprised on some level at the guest (?) list. Thinking too long and hard about these things (without the clarity of the Holy Spirit) is enough to drive someone mad as a hatter.
"Jesus answered, My kingdom is not of this world: if my kingdom were of this world, then would my servants fight, that I should not be delivered to the Jews: but now is my kingdom not from hence. Pilate therefore said unto Him, Art Thou a king then?" (John 18:36-37a)
In this substance
Urban legend has it that Robert Johnson sold his soul to the devil at the "crossroads" for his musical talent. Who knows. Listen to Andrae Crouch recount his story as to when his itinerant minister father told him to take a seat at the piano during a sermon. Andrae says his "ears just popped" and he could afterward play having never practiced. The proof is in the pudding. But in the case of Christianity, how one lives their life after Jesus comes calling is what tells. Johnson, in the lyrics to Crossroads says "save me if you please". There's hope. But this isn't our game.
Jesus says regarding serving and servanthood: "If you know these things, happy are ye if ye do them." (John 13:17) Contrast this with Paul's explanation of atavistic and innate morality among the "Gentiles", "which have not the law," and "do by nature the things contained in the law." (Romans 2:14) When one hears about Jesus and refuses Him, I believe judgment begins slowly. This might sound scary but only if you see time from without and hold the "keys of hell and of death." (Revelation 1:18) And have the deepest and irreproachable unconditional love. I am not Him, thank God. This stuff is deep and abstruse and wiredrawn (in a word: byzantine) and far above any and every human's paygrade. Should the Lord intimate something to your heart and show you someone on a slippery slope, it's because He trusts you to know and pray about it and leave it in His hands. (Life is beautiful.) But as we are responsible to Him for ourselves first, best to start there and work our way out.
"Hast thou faith? Have it to thyself before God." (Romans 14:22a)
"Jesus saith unto him, If I will that he tarry till I come, what is that to thee? Follow thou me." (John 21:22, emphasis mine)