Let me start off by saying that I don't think you should take a pill to end your life to avoid pain and suffering.
There, I got that out of the way.
As a Christian my perspective on life is different than someone who doesn't know the Lord. Although I would never want them to legalize assisted suicide, I really cannot expect anything different from an unsaved person who is suffering. If they do not believe in hell, then the thought of leaving behind suffering even to enter nothingness might be appealing. It's obviously a wrong choice.
As a Christian, we have heaven to look forward to. Heaven is a place where there will be no more suffering or pain, but God will let us come in His time. He tells us through Paul, "For I reckon that the sufferings of this present time are not worthy to be compared to the glory that shall be revealed in us." Romans 8:18
God doesn't deny the fact that we have something wonderful to look forward to in heaven.
Philippians 1:20-23 says it well from Paul, "According to my earnest expectation and my hope, that in nothing I shall be ashamed, but that with all boldness, as always, so now also Christ shall be magnified in my body, whether it be by life, or by death. For to me to live is Christ, and to die is gain. But if I live in the flesh this is the fruit of my labor: yet what I choose I wot not. For I am in a strait betwixt two, having a desire to depart, and to be with Christ; which is far better. Nevertheless to abide in the flesh is more needful for you."
When you first begin this passage, if you did not know the heart of Paul, then you might have some questions.There are several important things we can gain from Paul at this point in his life. He was getting old. He had seen many things. He had suffered more than any of us ever will. He wanted to be with Christ, so in essence, yes, he wanted to die, but in his death he says that he wanted to magnify Christ.
Can a suicidal death magnify Christ? The answer is no. All it says is that God doesn't know what He's doing when He gave me this illness or let me start having dementia, or gave me this or that. That thinking does not magnify Christ. The only death that does is that which is God's timing and His alone.
The gain for Paul in death would be heaven with no more suffering and no more dealing with difficult people like us. It was as if he was speaking out loud about his life/death choice.
What made the difference? Selflessness made the difference. In the end, he made his choice.
"Nevertheless to abide in the flesh is more needful for you."
Paul knew that although he might only have a few more years, God wanted him to serve the people for as long as he had. He made the selfless choice. That is really the decision before anyone choosing life/death. Am I going to be selfless and live for my family even if I'm suffering, or am I going to live selfishly and end the suffering?
Now, I don't know how seriously Paul was thinking about this. I'm not saying He was suicidal, but he desired heaven, yet He knew that God had a purpose for him, because no matter who we are, where we are at in life, and how much we are suffering, God has a purpose for us until He ends our life.
If you don't know the Lord, then you don't understand, but you must choose the selfless way; you must choose life. If you do not, then your suffering will be far worse than anything you could experience in this life.