Do you think that in US/Western churches today we focus too much on knowing scripture in the intellectual sense, and not enough on living it? If we did not explicitly say that we are Christians to our friends and acquaintances, would they make the same observation of us as the people at Antioch did - Namely that we are like Jesus!So, is right behaviour more important than right belief?
In drawing men to Christ a love of Christians for their brethren is attractive to those on the outside; they see our love for one another and that testifies to the love of God. As Jesus prayed,
I do not ask for these only, but also for those who will believe in me through their word, that they may all be one, just as you, Father, are in me, and I in you, that they also may be in us, so that the world may believe that you have sent me. The glory that you have given me I have given to them, that they may be one even as we are one, I in them and you in me, that they may become perfectly one, so that the world may know that you sent me and loved them even as you loved me. Father, I desire that they also, whom you have given me, may be with me where I am, to see my glory that you have given me because you loved me before the foundation of the world. O righteous Father, even though the world does not know you, I know you, and these know that you have sent me. I made known to them your name, and I will continue to make it known, that the love with which you have loved me may be in them, and I in them. (John 17)There is also a place for telling the truth. Demolishing arguments and explaining the truth to unbelievers. In Athens Paul reasoned in the Areopagus and some believed (Acts 17).
So both our behaviour (love for each other) and our reasoning (explaining the truth) are important in attracting men to Christ.
But what in our own lives? How do we please God (though that may also influence others around us)? We are to please God first, even if unbelievers find this unattractive; we are the smell of Christ, fragrant to the elect and a stench to the rebellious.
For we are the aroma of Christ to God among those who are being saved and among those who are perishing, to one a fragrance from death to death, to the other a fragrance from life to life. (2 Corinthians 2)In our pleasing God it is right behaviour which is important. Jesus frequently states that those who love him will obey his commandments (John 14). We must obey him even when we struggle to understand him. In contrast it is possible to have right belief but not live it, or at least try to live it. Teaching people the truth but refusing to live it is hypocrisy; a practice Jesus frequently condemned. Orthopraxy triumphs orthodoxy.
An aside, doing the right thing when you think it is wrong is not recommended. For example eating food that has previously been offered to idols means nothing intrinsically as there is only one true God (1 Corinthians 8, 10). But if you have qualms about it you should avoid it. Eating food when you think the act offends God is an offence against him.
So why the huge emphasis on orthodoxy? Because belief and behaviour cannot easily be separated. Belief does actually lead to behaviour. Wrong belief frequently leads to wrong behaviour. So while one is to obey God, thinking you are doing God's will when in fact you are not is not obedience. Sincerity, while of some value, does not excuse sin. This is why we must continually return to Scripture. We must renew our minds to be conformed to be like Christ as well as obey him as he asks of us.
Do not be conformed to this world, but be transformed by the renewal of your mind, that by testing you may discern what is the will of God, what is good and acceptable and perfect.There is a further benefit of learning truth: it becomes our default thought pattern. So when we face difficulties that challenge our emotions the struggle doesn't automatically cause a crisis of faith. Expecting suffering because we are told it will come may not make suffering any easier. It is, however, more likely to encourage us to ask God's help in our pain and less likely to see us asking questions like, "Is God real?" or "Does God love me?"