My experience is that there are things more easy to determine, because they are stated in plain words and/or various other scriptures fit with them.
One example, I personally understand, is that the Bible clearly says we become saved by trusting in Jesus for all our Heavenly Father desires with us > Ephesians 1:12. But there are people who insist that one must say a prayer or get baptized and/or other things. So, then is when you can have a lot of arguing and accusing, back and forth. But if we consider all it means to trust, this goes way beyond just copy-catting what others tell people to say and do.
Well, that can be like how, if a country attacks you, the enemy is part of your war plan but the enemy is not a welcome part of the strategy. And the main purpose of the plan is to continue your nation's culture of benefit. The main part of the plan is not only to defeat the enemy, and certainly not only to spend a lot of time only or mainly on beliefs about the war plan and the enemy.
Like this, yes sin is in the plan, but not the main or the welcome part of it. And Jesus is our Husband and we are being conformed to the image of Jesus > Romans 8:29 < this is the main plan with its main love purpose. All else is secondary, I would say.
First, there are people who are not with God, at all. They can pass themselves off as being Christians so that people say, oh look at how those mixed-up and fighting Christians are. Ones like this have conducted even religious wars and various other hurtful things. But if they have been leaders in certain groups and denominations, ones can be in denial about this, and keep on promoting their wrong ideas.
I would consider that God is not allowing such people and their activities, meaning it is not His will and they do not have His approval. But His priority is to correct whoever are His children; so in case a wrong person is not a child of God, that person could go all one's life the wrong way, if one does not seek God for Himself and trust in Jesus and submit to our Father's correction bringing His love's perfection > 1 John 4:17.
But, even among those who are God's children, we can be wrong because of our own immaturity and ways we have not given up our selfish motives. In our selfish stuff, we can see things the wrong way and so have wrong ideas. I suppose you have noticed how a human can have a way he or she wants things to be, and so he or she believes what fits with that.
We need first, then, how God corrects us in our character so we can better understand Him and His word.
So, then . . . if a Christian is still not mature, the priority is to correct and mature the person, not only get his or her ideas straightened out. So . . . because of priority, God may allow certain ideas to continue.
Also, if wrong people keep pushing their wrong ideas, this can help really Christian people to spot who the false people are > 1 Corinthians 11:19. But we can also tell by how wrong people can be dictatorial and controlling, which is against how Peter says true exemplary leaders are to relate >
"nor as being lords over those entrusted to you, but being examples to the flock." (1 Peter 5:3)
This is, of course, in God's word; so any of us can feed on these things and then use them to help us know who and what to trust. As we get to know the real deal, it becomes more and more easy to spot what is counterfeit . . . like how Secret Service trainees first are told to examine a real dollar bill, instead of studying the thousands or millions of fakes they have in custody. You can tell, by where someone calls your attention, how much he or she emphasizes what is most important, or is decoying you elsewhere. If you get familiar with the Bible, you can see what needs the main attention. How to become in our character is the first thing Jesus dealt with, in His Sermon on the Mount. But you can see how ones can, right away, get away and be arguing and confused . . . because of their decoy questions with evasion of simply seeking God to cure our nature in His love (1 John 4:17, Ephesians 4:2, Ephesians 4:31-5:2) and then personally guide us in His peace (Colossians 3:15).
You say, "feel" close to God. I offer, that if a person is "one spirit with Him" (1 Corinthians 6:17), one is
more and more experiencing how God is so absolutely beautifully wonderful in Heaven-quality love which is pure and pleasant with "the incorruptible beauty of a gentle and quiet spirit" (1 Peter 3:4). This will cure our nature and personality. So, yes we will feel this, but because it has become our new reality in us. And this gentle and quiet and unconceited and unegotistical love has almighty power to make us immune to fear and all its personality torments >
"There is no fear in love; but perfect love casts out fear, because fear involves torment. But he who fears has not been made perfect in love." (1 John 4:18)
Yes, you will feel if fear and its torments can't get the better of you. But you feel this because this is a reality, in God's love. And so, God's children who are discovering this love meaning of His word will show and tell this

Meanwhile, others might call themselves Christians, but they will stay busy with arguing and promoting their ideas and practices and trying to figure out what certain Bible passages mean - - where the Bible does not say what they mean. But, instead, we first need to seek our Heavenly Father to correct and cure our nature > Hebrews 12:4-11; then we are in His light so we can see better > Philippians 1:9.
We see in life how beliefs can be effected by if we love or if we hate. For one example, if you love a certain black person you might know personally, your love will have you believing things very different from those of someone else who hates that exact same black person. Plus, our motives can greatly effect how we are ready to understand God's word. The Bible is not exactly friendly with the motives of a number of people.
If I don't understand something, there can be different reasons for this. It can be because I need to mature more so I am ready to handle it > Hebrews 5:13-14. Also, if I try to take a short-cut to only learn ideas, without getting personal correction which God knows I need, then I can get in problems. Also, if I go to wrong source people, I can get ideas which will not fit with the right interpretations of the Bible > there are things you can get straight about, just by reading one Bible verse, but ones can take that question and write books about it . . . selling a lot of books, plus getting a lot of speaking engagements, when one verse speaking for itself might tell you more than all that person's books and lectures combined!
A Bible passage can be difficult because of how I have set myself up with things to keep me from understanding something correctly.
So, we might need to table something while we get correction we need. Also, it simply may not be God's will for us to know something, plus the questions we are asking could be misleading our attention, and we need to get or stay on track where our attention belongs.
For an example of how one could ask misleading questions > if you buy a car and ask how fast it can drive, this could get you in trouble if you try to find out. Or . . . to use a silly example > if you get to arguing with your wife about how to find and use the hatchback of a car that does not even have one > that argument could go on for a while, while you do not discover all that really is in the car. Likewise, there are things which are misleading and sidetracking questions, and therefore not what God might be interested in answering.
But in case we are looking for a right thing, but don't get it right away . . . we might table it, but by praying for how and when God pleases to teach us. And feed on all He does have for us now.