Forcing Your Convictions and Stumbling the Christian Sibling is NOT the Only Outcome of Precise Instruction for the Soul
It's wrong to stumble your Christian sibling. If she thinks that smoking is sinful, don't smoke in front of her. If he thinks that a demonic practice is held in the local butcher's shop, don't eat meat in front of him, because his conscience will be hardened, and you will have stumbled your brother. That's from the the Bible, in Romans.
It's been said from the pulpit that you cannot force feed a Christian to cause growth. You cannot replicate your convictions in your sibling due to this principle. But that saying has grown too wildly out of proportion and taken on new meanings in the fervent telling. We can and should tell our Christian sibling about the benefits of capturing every thought and forcing it to obey Christ! And we can do at least as much as you allow with a therapist, to track down the cause. Just don't be like the naturalist therapist and try to hide the guilt somewhere invisible. Remove the cause, and the effect will go away. We know this. We are afraid, in many entire congregations, to help each other in love. If you think it's wrong, don't go against your conscience, but if you can see it, then there is life and liberty and joy and rescue from the domination of your flesh which your Christian sibling is fully aware of if you can just get him to tell you like he thinks in his mind or tells his prayer group (because you have to know what to pray for, no? It's an old, sad joke. Don't worry about it).
If you love your sibling well, then you can guide that Christian - even children! - to take control over the sin-nature. It's always prompted by Scripture, though, so don't use your conclusions too much, but stick close to what God has told us. Tell it in love, and not the duty-bound mimicry of love, either! You've been warned! But if it's in love, God will help you see its useful fruit in the life of your sister, your brother in Christ, and, just maybe, she'll know how and be willing to help you in the same way in return.
You have to start by seeing sin as a burden. You're not mandating duty, you're supplying support to ease the burden, like a skilled doctor attaching a back brace. Shining light on the nature of the sin and relating it to the good thing that it twists is very helpful, but we hardly do that in church. It's sad, because loving God first would see us strive to find ways to help, like this one, and loving ourselves second along with our neighbor would give us confidence to apply the help, because love casts out fear and it mellows embarrassment. We are rightly ashamed of sin, but confessing it to each other as well as to God helps us dominate our flesh in the spot where the sin is, we stop protecting that spot, and we allow God to cauterize it and then heal it.
Our souls - mind, will, emotions, and any other part of the internal person - are the same. Our personalities are not, but there are similar situations in the experience and states in the soul in most people. We could, if we were very careful, write something of a manual on the human soul which would be generally applicable. Take every thought captive to make it obey Christ! And be glad as your love becomes more everyday true with your pew-mate this week. Try to find out their name, make sure they agree with salvation doctrine, and then, if you can, ask them if you can sleep on their couch (just because). Push them gently to give you something, but only if you know that they will! That's the key. Don't stumble them, but stretch them.
We have all sorts of surface love with each other - smiles and handshakes and old peas in the church basement a few times a year. But do we know each other? Why not? We call each other "brother" and "sister". It's not a mere saying. If you love Christ, you'll not let your parents stand in your way toward Him, but your Christian sibling is on the same journey, and so you can go together! Meeting in church changes our demeanors very much, but it's not right. It's quite, quite fake. Some have lightened up on that, but the love is still not very deep yet in most congregations. Look at the types of things Paul taught people he barely knew and who just came to Christ! We are afraid to go deep, because we think that we cannot force feed the sibling what we have convictions about this month or year. But that's wrong-headed. People are wiser than we let on, and we can take more than the rudimentary scraps that speak to the lowest bar. Winsome stories that illustrate a big hug cannot replace God's excellent teaching. Your feeling is not The Holy Spirit, but your knowledge of God's Word is often reinforced by Him. Help the siblings well!
God is love. God is truth. God's justice is fearsome! You've been warned, but you've also been encouraged.
John 7:24 goes along with "Judge not, lest ye be judged". Tell each other the truth in love.