God knew as humans we would need a tangible image of Him to fully accept him, a jolt, if you will. As for the Trinity, I don't think our minds can ever grasp the full scope of that, but I believe it will make sense to us in the afterlife. I love the example that was given one person, but three function, a wife, a mother, a daughter. I think that God wants us to rely on faith to believe! "Faith is believing the possible and trusting the impossible." That's what makes us better Christians, believing in the impossible!