Sometimes I start to feel discouraged when I contemplate what Christianity has become. It seems as if everything man touches becomes corrupt in one way or another. I don't believe that christianity is supposed to be complex, or obscure, or difficult in any way. But just look at it today! All those churches with competing ideas about everything. All those rules. All those millions of pages of written material. Universities offer PhDs in the subject! Yet all that matters is saving the soul of the brother or sister standing next to you. It's insanity.
Think for a moment about Jesus teaching His people. He speaks to them during His Sermon On the Mount. Who here would say that any person sitting in that gathering listening to the words of the Lord, and who actually believed what He said, who actually recognized Jesus as Messiah, and who gave himself or herself over to the Lord on that day, was not saved, not a Christian, not as righteous in the eyes of God as any "Billy Graham" or Pope among us?
And that's it, all of it. The Word of God, sincere belief, and a commitment to Jesus Christ is all it takes. There was nothing else necessary then, and there is nothing else necessary now. All the rest of it, all the stained glass, libraries of books, prancing priests, pipe organs, and Sunday picnics are unnecessary. And, they can be dangerous, because they can fool people into thinking that is Christianity, when it isn't.
What I write here is not Christianity, and what St. Paul wrote to the Roman Church isn't Christianity either, regardless of how Divinely inspired it was. To find Christianity, put yourself back on that hillside, and let the Words of the Lord Jesus into your hearts and minds. That's where you will find it.
Jesus told His disciples to teach their disciples to obey whatsoever Jesus had commanded them (Matthew's Great Commission at the end of ch. 28). In Matthew, such commandments are not limited to, but are surely concentrated in the Sermon on the Mount. To be a disciple of Jesus means to obey Jesus' commands.
Yes, I think justification by faith alone is not inconsistent with that, for the justified obey by grace, but to try to keep closer to the topic, (1) disciples of Jesus function together in what is known as the church and (2) obeying Jesus in church context (e.g., per Matthew 16) or influence may entail certain consequences such as pedagogical stained glass windows or Bible commentaries or clergy and so on--even if such things can be a hindrance as well as tools in building God's church. What concrete things might be helpful in baptisms and in making disciples?
Nonetheless there is, I think, much to be discouraged about particularly in the West regarding the spiritual health of the Christian religion (if I can put it that way). If you are looking for encouragement in doing better, one can perhaps start in the route of looking for causes, of which there are many. However helpful that exercise may be as a tool (and it can be if God is pleased to use it to grant repentance), it can also be rather discouraging or end in angry finger pointing--a less than helpful application.
One (other) helpful avenue of encouragement in my experience is holding a broader view of God's work. The West is not the world, only part of it. If the church has problems in my area or in my circles or if bad news travels fast, remember that God is at work in places I may not know--or if I read for example that the church is growing faster than the population (biologically) in most nations of the world outside the West, I am encouraged, as Paul seems to have been in remembering congregations outside his "own" charges (like the one in Colossae). Reading about what God is doing elsewhere (or in other times, for the church of Jesus is one) can lead to thanksgiving to God.
A further thought has already been expressed on this thread in so many words, I think: through endurance and the Scriptures we may have hope (from Rom. 15:4). The author of Hebrews would seem to agree; the church body members are obliged to encourage and exhort each other in order to persevere--in obedience to the commands of Jesus and in prayer.
Yes, the trappings of religion can be abused. Even the bronze serpent meant for good became Nehushtan the idol. Yet the church perseveres because Christ is its builder, and He has commanded us to persevere until the end.
Some years ago there was a wind storm in our area which tore down branches and limbs and whole trees so that the streets were blocked and littered and gaping wounds showed on many remaining trees. I was sad until I remembered that God's trees are still growing. Quietly, such that I do not notice. So with God's kingdom: As a mustard seed or as leaven in a lump of dough.