Everything that happens to you is a direct result of your own actions. Sometime the response is within a few minutes, sometimes not for decades but the results of your actions are unavoidable. And, as you say, there is no such thing as coincidence; all things happen for a reason and for every person you meet, you meet to learn something or for them to learn something from you.

Yes, you may meet someone who is a complete a** and have no idea why you had to endure that meeting but there was something to learn from it, often in forcing you to see a part of yourself manifest in that person but denied by you. Those are great times to learn and until said thing is learned you'll keep being forced to meet someone who is there to remind you there is a lesson you need to learn to grow in spirit. God, by any name, gives up on no one and the universe is there to nudge you in the right direction. Your "gut instinct", if followed, allows the universe to guide you. Try not to overthink things because that allows the earthly ego to send you in the wrong direction.

Live your life with a quiet, unwavering faith that all is meant for your own good and good things (spiritually) will become the norm in your life on this plane of existence.