Contrary to the old sayings, ignorance is not bliss and what you don't know can hurt you and others very much. In addition to sin, ignorance was the cause of the worst crime ever committed — our murder and execution of God by crucifixion on Calvary. Paul taught: "None of the rulers of this age knew the mystery; if they had known it, they would never have crucified the Lord of glory" (1 Cor 2:8). We "perish for want of knowledge" (Hos 4:6).
If we know God the Father, the Son, and the Holy Spirit, we have eternal life (see Jn 17:3). But if we don't know the Lord, even if we say we do (1 Jn 2:4), we are caught up in "a great war of ignorance" (Wis 14:22). In this state of war and ignorance, people "celebrate either child-slaying sacrifices or clandestine mysteries, or frenzied carousals in unheard-of rites, they no longer safeguard either lives or pure wedlock; but each either waylays and kills his neighbor, or aggrieves him by adultery. And all is confusion — blood and murder, theft and guile, corruption, faithlessness, turmoil, perjury, disturbance of good men, neglect of gratitude, besmirching of souls, unnatural lust, disorder in marriage, adultery and shamelessness" (Wis 14:23-26).
The Lord doesn't expect us to know everything. He may not even expect us to know that much. But He does expect us to know as much as possible. Know the truth. Know the teachings of Christ's body, the Church, especially those in the Bible. Know God (Phil 3:10).