English Standard Version (ESV)
At a certain point, we have to admit that there are things we simply cannot grasp about God -- there are ineffable qualities that escape our ability to comprehend. We get into trouble when we become so certain of things that our minds cannot be changed, because then we stop listening to what God has to say because our minds have formed a certainty.
It would have been easier for Peter to shut off his mind and stay focused on what has always been true. Instead, what Peter does is listen to the Holy Spirit call him into a new understanding of the Gospel. Peter could have remained in his old understanding that the Gospel was only for the Jews, but instead he allows God to change his mind, to challenge his way of thinking, and through Peter the Gospel flows into people who had not previously heard the Good News.
It requires a certain humility to be a Christian, because we aren't God. We don't know all the answers -- we understand what we can through the lens of Scripture, and we trust that God will give us the strength and wisdom to serve and love those around us.