I believe that a person who plans with certainty to take their own life is judged the same as if dying naturally or by other means.
If that person knows the truth of Jesus, and understands the message of God's salvation by the Son, BUT yet can't handle life as they know it, God doesn't take away their standing with him, however once this person knows the truth of God when they meet Him and understand what they did, they must live with this, however again Jesus will cause this person to advance past this sin against himself and his God, by choosing to take what was not his to take.
There is nothing about this in the Bible and anyone who claims a passage is addressing this is ripping that verse out of context and mis-using the word of God.
The Bible is silent on this act because of the human reasoning factor when this act is calculated.
for instance
A person likes going fast and knows that going fast in a car on a particular road will 99% kill him, and so he attempts it and dies, what was in his mind at the time...
lets say, He said within his own mind, I don't care if I die, so I will try it......is that not the same....He doesn't care if he dies and welcomes it.
The one who reasons to put a gun to his head is in the same mind state, just because the guy with the gun leaves no 1% way out, which he already said he didn't want anyway and didn't care if he had it doesn't mean anything here.
Anytime one puts himself into a situation where death is the 99% plus chance, one has chosen to die at ones own choosing.... so this is why it is not covered in the Bible.
BESIDES
Like I said, if that person is in a state of existence where they know they have believed the truth of their standing with God, and trusts it, do they not stand to their Lord?, even though they think of participating in an event that would kill them.
I have known pastors sons who have taken their lives, and lived in faith in God, however they have lost their way in sin and can't seem to get past the shame of their actions.
Job said, God said, he created the dragon type animal which caused FEAR in the minds of all who look at it.
God create animals with meat ripping teeth, To attempt to take your own life before that horrible being eats me, is a good thing, God loves me still

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I will not go by mythical religious so call spiritual thinking here. The bible is silent on suicide all we can do is use our God given common sense on this topic.
Ash