Beliefs matter. Our view of God matters. Doctrine matters.
This may seem somewhat contradictory to my earlier posts, but there is an important clarification I need to make:
While subscribing to one systematic theology, eschatology, soteriology, etc. may not remove you from the body of Christ, having correct doctrine does matter because it affects how we live.
If our subjective reality doesn't line up with objective truth, then we will not realize what blessings we have, exclude those from God's love who shouldn't be excluded, and not live life to the fullest.
For example, if you've been a follower of Jesus for ten years now, consider your level of knowledge and spiritual maturity ten years ago (twenty, thirty, fifty years if necessary).
Have you grown in knowledge? Have you matured at all?
See, you aren't more saved or less saved than you were (if we think about salvation in strictly binary terms). You had access to all spiritual blessings even if you weren't aware of the blessings you had to the extent that you do now.
So, beliefs matter which means studying the Bible and debating and discussing matters.
Whatever doctrines we accept affects how we live our lives even if the view of God or Jesus we accept isn't in line with reality.
A wonderful example of this is the story of the prodigal son.
There are four stories told in the chapter (at least). Two of the stories are negative and held by the sons, but the other two are positive and told by the father. Really, there are only three, but speaking of them as four makes it easy to compare them.
1. The story of the prodigal son: “Father, I have sinned against heaven, and in your sight; I am no longer worthy to be called your son; make me as one of your hired men.”
2. The story of the father: “Quickly bring out the best robe and put it on him, and put a ring on his hand and sandals on his feet; and bring the fattened calf, kill it, and let us eat and celebrate; for this son of mine was dead and has come to life again; he was lost and has been found.”
We've probably accepted the first story at some point in our lives: we aren't worthy, we're failures, we don't even deserve a shack in Heaven. THIS STORY IS WRONG.
The father had nothing but undying love and compassion for his son. Before the son ever woke up, the father was already watching for him. He didn't deserve that love from the world's point of view, but the entire point of the story is to circumvent conventional wisdom. The son deserves the father's love because the father decided that he did.
Don't let anyone tell you that you don't deserve God's love. That's not for you or them to decide. That's God's decision. And He decided you were worthy before the foundation of the earth.
“Well that's not fair.” WHO SAID IT HAS TO BE? That's mercy and grace.
Our neighbors and enemies deserve our love, not because of anything that they did but because of what God has done for us.
3. The story of the older brother: “Look! For so many years I have been serving you and I have never neglected a command of yours; and yet you have never given me a young goat, so that I might celebrate with my friends; but when this son of yours came, who has devoured your wealth with prostitutes, you killed the fattened calf for him.”
4. The story of the father: “Son, you have always been with me, and all that is mine is yours. But we had to celebrate and rejoice, for this brother of yours was dead and has begun to live, and was lost and has been found.”
Why did the son live like a servant? Because of the story he told himself. He didn't realize that everything the father had already belonged to him.
He didn't have to work for it. He didn't have to earn it.
Those were assumptions he made because of the story he told himself.
Why didn't he get a party? “You have not because you ask not” comes to mind.
The point of this is that the stories we tell ourselves matter. They affect how we live, how we treat others, and how we view God.
Some stories people tell cause them to exclude many from the body of Christ. Other stories people tell leave them anxious and afraid of God. We need to work to discard those stories for the one that God tells: “while you were sinners, I died for you. I love you, but not because you love me. I'm always watching and waiting with the fatted calf, the robe, the ring, and the sandals to celebrate with you because I decided that you deserve it despite what you think.”