The only second chance is those that are not Christian and tribulation as mentioned in revelations and the bible says that most people will not make it through tribulation. If you died today and are not right with God of Christianity than you would not go to heaven and there are no second chances in that.
I disagree because John saw a great crowd of slain saints coming out of the tribulation that no one could number:
9 After these things I looked, and behold,
a great multitude which no one could number, of all nations, tribes, peoples, and tongues, standing before the throne and before the Lamb, clothed with white robes, with palm branches in their hands,
10 and crying out with a loud voice, saying,
"Salvation belongs to our God who sits on the throne, and to the Lamb!"
11 All the angels stood around the throne and the elders and the four living creatures, and fell on their faces before the throne and worshiped God,
12 saying: "Amen! Blessing and glory and wisdom, Thanksgiving and honor and power and might, Be to our God forever and ever. Amen."
13 Then one of the elders answered, saying to me, "Who are these arrayed in white robes, and where did they come from?"
14 And I said to him, "Sir, you know." So he said to me,
"These are the ones who come out of the great tribulation, and washed their robes and made them white in the blood of the Lamb.
15 "Therefore they are before the throne of God, and serve Him day and night in His temple. And He who sits on the throne will dwell among them.
16 "They shall neither hunger anymore nor thirst anymore; the sun shall not strike them, nor any heat;
17 "for the Lamb who is in the midst of the throne will shepherd them and lead them to living fountains of waters. And God will wipe away every tear from their eyes." (Rev. 7:9-8:1 NKJ)
The came "out of the great tribulation", meaning they mostly are martyrs for the faith. But what if someone were slain protecting a Christian. But they themselves were not Christian. Are they to be damned forever?
I think not for it is written:
"For whoever gives you a cup of water to drink in My name, because you belong to Christ, assuredly, I say to you, he will by no means lose his reward. (Mk. 9:41 NKJ)
And our LORD Jesus Christ said this about the sheep who aided His brethren during the Tribulation:
31 "When the Son of Man comes in His glory, and all the holy angels with Him, then He will sit on the throne of His glory.
32 "All the nations will be gathered before Him, and He will separate them one from another, as a shepherd divides his sheep from the goats.
33 "And He will set the sheep on His right hand, but the goats on the left.
34
"Then the King will say to those on His right hand,`Come, you blessed of My Father, inherit the kingdom prepared for you from the foundation of the world:
35 `for I was hungry and you gave Me food; I was thirsty and you gave Me drink; I was a stranger and you took Me in;
36 `I was naked and you clothed Me; I was sick and you visited Me; I was in prison and you came to Me.'
37 "Then the righteous will answer Him, saying,`Lord, when did we see You hungry and feed You, or thirsty and give You drink?
38 `When did we see You a stranger and take You in, or naked and clothe You?
39 `Or when did we see You sick, or in prison, and come to You?'
40
"And the King will answer and say to them,`Assuredly, I say to you, inasmuch as you did it to one of the least of these My brethren, you did it to Me.' (Matt. 25:31-40 NKJ)
How do we know these sheep aren't Christians? Christians were raptured and came with Christ when He descended from heaven with His holy angels. They are seated there with Christ as He speaks to these sheep. Likely He points to them when He says: "These My brethren"
The Sheep cannot be Christians because this Judgment occurs while they are seated with Christ and His angels, as Kings and Priests. "These my Brethren (Mt. 25:40; Rm. 8:29) were "gathered" (2 Thess. 2:1) from the earth during Christ's coming in glory. They reign with Christ as Kings and Priests (Rev. 1:6; 20:4-6; 1 Thess. 4:14-18; 1 Cor. 15:51-58; Mat. 24:29-31; Rev. 14:14-16). Because they believed in Christ when physically alive, they do not "come into judgment, but has passed from death into life." (John 5:24). As Christ's "Brethren" they have authority to judge the unsaved with Christ (Mt. 19:28; 1 Cor. 6:3; Rev. 20:4), the "firstborn among many brethren" (Rm. 8:29).
So God is consistent, impartial and fair. He gives a second chance to everyone who dies IF they have not committed eternal sins. He gives the survivors of Armageddon who attended church but failed to commit to Christ, but who showed they loved Christ by helping persecuted Christians during the tribulation, a second chance when He comes.
Those who aided His Brethren against the Beast, hiding them, feeding them during the Tribulation, they are received into the Kingdom.
Of course, the TARES in the Church, the goats, are cast into eternal flame. That is their judgment Day, when Christ comes. Judgment starts first with the House of God.
Then the rest of humanity, those who didn't know the gospel well enough, or didn't take the make of the beast, get a second chance when they enter the Millennial Kingdom.
Not all pass that trial, just as not all pass the trial after death. Some followed Satan and joined Gog and Magog.
The children of the devil just can't live righteously, they don't want that.
But all who do, not one of them will be lost. If it could happen that a righteous God loving person end up in torments, God never would have created.
He would mourn their loss for all eternity. So He wouldn't have created if He didn't have the perfect plan to save all who love Him:
And we know that all things work together for good to those who love God, to those who are the called according to His purpose. (Rom. 8:28 NKJ)