There is this following saying attributed to St Augustine : Essentials, unity; Non essentials, liberty; All things, charity.
It is a good summary of how we should deal with matter of truth and matter of conscience.
I will paraphrase as such : Matter of Truth, unity; Matter of Conscience, liberty; All matters, love.
There should be absolute unity concerning matter of truth or doctrine. Any deviation from the biblical truth will be considered as apostate belief. We cannot agree to disagree on matter of truth. For example, if we hold the belief that Christ is the only way and others hold the belief that there is several ways to God including Christ, we are not traveling on the same road together anymore.
But concerning matter of conscience, we can have liberty to agree to disagree. One good example is found in 1 Cor 8 concerning eating food offered to idols. For those with knowledge will know that idols are lifeless artifacts and there is only one God who is spirit. They can have the liberty to eat without asking question when invited by the pagans to join their feast with the food offered to idols. But for those without knowledge, thinking that the food is defiled, they can choose not to eat as food does not bring us any closer to God anyway. The only concern is not to stumble the weaker brother in insisting on the exercise of our rights. Obstinate insistence on the exercising of our rights causing the stumbling of the weaker brother is sinning against Christ. Be warned.
The overarching consideration in all matters is to deal with love. As long as we put the interest of others above ours, we are doing well as we are following the example of our Lord Jesus.
Phil 2: 3-11 3 Do nothing out of selfish ambition or vain conceit. Rather, in humility value others above yourselves, 4 not looking to your own interests but each of you to the interests of the others. 5 In your relationships with one another, have the same mindset as Christ Jesus: 6 Who, being in very nature God, did not consider equality with God something to be used to his own advantage; 7 rather, he made himself nothing by taking the very nature of a servant, being made in human likeness. 8 And being found in appearance as a man, he humbled himself by becoming obedient to death— even death on a cross! 9 Therefore God exalted him to the highest place and gave him the name that is above every name, 10 that at the name of Jesus every knee should bow, in heaven and on earth and under the earth, 11 and every tongue acknowledge that Jesus Christ is Lord, to the glory of God the Father.