In his Wednesday general audience, Pope Francis uttered the words above; see the LifeSiteNews article for more context. This is utter heresy. It strikes at the very nature of God Himself. Any theologian worth his salt (and for that matter, anyone with common sense) will tell you that God is all-sufficient. He is all powerful and all-encompassing within Himself. He doesn't need us to somehow "complete" Himself; to insinuate otherwise would be to say that there was a time when He wasn't as omnipotent as He is now.
Read what St. Irenaeus had to say about the matter. It is worth noting that the excerpt comes from one of his works entitled "Against The Heresies". Heresy is exactly what the Vicar of Christ uttered yesterday. If his understanding of the nature of God is so flawed, it's no wonder that he flubs up so much else.
We must educate ourselves in the doctrines and truths of Our Faith. Only very few - even our shepherds - will assist us in that.