1- We didn’t choose to be created. Allah created us based on His wisdom and mercy. Giving us life is merciful in and of itself.
2- We need to seek nearness to God because He is the source of all goodness in the universe. The more we connect to him, the more we benefit. He doesn’t benefit. We do. The more we seek nearness to him, the greater our spiritual capacity will become. The more knowledge we’ll have. The more influence we’ll have in the universe, and the more enjoyment we will have. Material pleasures are the lowest form of pleasures. There are higher levels.
3- People consider such lives boring because they don’t understand them and they limit themselves to material joys. Many kids find adult activities boring, right? Why? Because their capacity is lower. Kids focus on things we may consider insignificant. It’s the same with spiritual and religious people. They find the greatest joy in knowing God, worshipping God, obeying God and seeking knowledge. It rejuvenates their souls. Secondly, I know many pious people who do have interesting and exciting lives. We just may not know about them. They do a lot of fun things, but halal and appropriate of course. Social activities, sports, traveling, etc… are some of they activities they might do.
4- Hell is the natural consequence of injustice/oppression, and of disconnecting oneself from God. God will forgive most people, but He threatens us with Hell in order to discipline us. Without the fear factor people don’t behave. If there are no police outside, would most people obey traffic laws? Probably not. Most people obey them out of fear of being fined or arrested.
5) A- Not believing in Allah is a big self-harm. By disconnecting yourself from your creator, you are greatly harming yourself. And it’s not just “preventing himself from higher spirituality.” One who doesn’t believe in God will eternally be in darkness, and this is the greatest harm to oneself.
B- If one doesn’t believe in God out of ignorance, then there is room for forgiveness. God may retest this person or forgive him. But if it’s out of arrogance and stubbornness, then this arrogance deserves punishment because it’s evil to be arrogant. Arrogance must be disciplined. There is wisdom in that.
C- One who abandons God’s path automatically follows the path of Satan. Satan is God’s enemy. Following his path requires punishment. A person who sides with the enemy of his creator and provider and sustainer deserves to be punished according to reason. Justice necessitates that.