Romans 14

In this passage, we see 2 groups of people in the church. Paul called one group have stronger faith than the others, the other group have weaker faith than their counterparts (2), but none of them have the right to deem themselves better than the rest, let alone judge, for only God have the rights to judge (3, 4).

here also Paul mention some things that shouldn't be the cause of dispute: unclean food, sacredness of certain days, and so on. We're agree with this as we think the most important thing of being Christians is whether we're adhering to a correct doctrines, salvation by grace to faith, sanctification process and so on and so forth. As long we're agree with the same core values, we can live with whatever different way of living that we might have.
17For the kingdom of God is not a matter of eating and drinking, but of righteousness, peace and joy in the Holy Spirit,

Having said this, Paul also taught us not to be a stumbling block for the other folks who might not have the same way of thinking as us. For instance, if you think all food is clean, (Paul think the same way, 14) you'd still better not to eat all of those in front of other ppl who think otherwise (13), doing so will make your peers stumble (15) and this will annul whatever right thing that you do (23). But isntead whatever we do, should be aimed for mutual edification and peace (19).