Coincidence has been defined as: "A remarkable concurrence of events or circumstances without apparent causal connection." But enough of them and we start to think: "something or someone is involved here. It is only after looking back on my life that I could see what I once thought were a lot of really just neat coincidences were actually encounters with God or small miracles. Do these miracles happen to everyone? I thinks so. In the Bible we read that "...in Him (God) we live and move and have our being"-Acts 17:28 NIV. The problem is that too many of us never see these encounters with God as anything more than just wonderful little coincidences.
An alternate possibility:
I compare coincidences to what lawyer's call "circumstantial evidence." A good trial lawyer will say that you can build an airtight case on circumstantial evidence. Of course, it takes a lot of it. I submit that our lives are full of "coincidences" or "circumstantial evidence" that God is and that He is at work in and around us. These coincidences are His call for us to see Him and trust Him.