Supposedly the church exists for the very purpose of proclaiming the whole truth of Jesus to the world. Given that the source of that truth is said to be the Bible, one should rightfully expect that the church actively and purposefully deal with all of the truth revealed therein, or at least explain why certain portions are inapplicable today and therefore not a part of current truth. In my experience the issue of what lessons in scripture do not teach us today is rarely if ever mentioned in formal classes and sermons.
Instead, what I generally see is the random use of Old Testament passages, which were clearly directed originally to Jews only, to demand compliance with the provisions of the OT Law and to draw conclusions about God's nature and operation in the current day. Thus things like tithing are enjoined on church members when the word tithe(s) appears no where in the New Testament as a church mandate. Notably, the insistence on tithing as a continuing requirement is the very source of church finances, so there is little wonder that it has been conveniently extracted from Judaism to find a home in Christian Orthodoxy. Jesus was certainly a Jew who ministered on earth to His people, but that provides no reason to randomly bind strictly Jewish practice on present day church members. Did Jesus come to proclaim righteousness under a universal Judaism or something else really new?
On the opposite side of the fence, I note any number of New Testament scriptures which garner scant interest from sermon preparers and Bible class teachers. Jesus and Paul both taught the disciples to live in accordance with the Golden Rule (Matt 5:44) even when dealing with their enemies (Romans 12:17-21). The church is very keen on noting enemies, but I observe no interest in treating them lovingly and overcoming evil with good.
In like manner both Jesus and James clearly show in their teachings that there are no big and little sins. Yet the church incessantly picks out certain sins to mark as a clear sign of God's rejection, while the "petty" sins of the church are tolerated or even encouraged. Jesus repeatedly commanded His followers to straighten out their own lives before they could turn to judge others, knowing full well that those who followed those instructions would be too busy to turn any attention outward. Not so the church. Their greatest pleasure is to note everyone else's shortcomings and then declare their moral superiority because they have achieved God's forgiveness through right doctrine and practice.
In Galatians 5 the Apostle Paul noted the characteristics which distinguish the normal human mindset from that of the spiritual man. These gifts- love, joy, peace, and patience, for example- are often mentioned by the church as marks of the Christian, but then they insist that every God follower is a warrior and must therefore engage in all manner of conflict, alienation, segregation, and condemnation, making the practice of these fruits an impossibility. Humility, meekness, kindness, and concern for His fellowman may be the mark of Jesus but the church's general attitude and practice make a mockery of any pretense that the church members should actually emulate Jesus in these attributes. They are, instead, too busy with other more vital issues, like opposing evil through redemptive violence.
Jesus proclaimed the arrival of an internal, invisible kingdom but the church gives us an external, highly visible institution in its place. Paul wrote in several places that the message of Jesus had already reached all the world but yet the church justifies its existence with the contention that they operate yet to carry that message to the entire world. How did the church supplant the internal, invisible kingdom and do so to supposedly complete a mission already completed according to Paul 2000 years ago?
The more times the church has to resort to qualifying these Bible lessons in order to maintain its current doctrinal positions, the more obvious it becomes that their approach to Bible interpretation is anything but simple, straight forward, and transparent. The entire interpretive scheme of the church is dependent on base assumptions which are the choice of the interpreters. Those choices most often reflect an inherited predisposition to see God, His nature, His purpose, and by extension the church in a certain light. Out of these choices flow a need to qualify and largely neglect many scripture passages which don't literally support the chosen assumptions.
The church preaches their version of a truth, using some part of the Bible as support. However, any contention that they teach and deal with all that Jesus and the apostles taught in the Bible is a very real stretch. In the final analysis no Bible interpreter can realistically claim to tell the truth comprehensively. Any human claim to know the whole truth of God is impossible to believe. Any assertion to deal with all the truth has to be rigorously demonstrated to the satisfaction of at least a majority of those hearing the claim. I have personally never seen or heard of that biblical understanding, including my own. Attempting to confine the whole truth about God to the pages of a 2000 year old book is preposterous. Surely no one believes that all such truth can be conveyed to the human mind in human language. Many, but not all believers, seem to accept that God can communicate with them in non verbal ways. Prayers for wisdom and claims of Holy Spirit guidance imply as much. All such beliefs demand an acceptance of truth emanating from outside the Bible.
As long as human effort and wisdom must be applied to the Bible in order to draw out its message, we remain at the mercy of our own limitations in determining even a portion of the truth. Given those limitations I suggest that great humility is demanded of any interpreter. Such humility precludes the insistence that I am necessarily right in my understanding to the extent that others are obliged to accept it as the truth, the whole truth, and nothing but.