Apostle Paul pleaded for tolerance between those who are weak in faith and those who are strong in faith, and he taught that believers need to accept each other

Romans 14:1
Accept other believers who are weak in faith and don't agrue with them about what they think is right or wrong.

When we condemn each other, the devil GLEES WITH PLEASUREWe should stop condemning and belittling each other. Rather, We should learn to worship God with a united voice and spirit hence putting the devil to shame.

Romans 15:6
"Then all of you can join together with one voice, giving praise and glory to God, the Father of our Lord Jesus Christ."

Apostle Paul addressed specific issues of whether believers need to pratice certain requirements of the OT law and of Jewish worship. Back in those days and to this very day, some believers use the word "Non essentials" to describe beliefs or pratices that are neither required nor prohibited by Scripture. On such issue, the bible said "Christians must accomodate a variety of opinions. Back in Jesus time on earth, Jews where prohibted to mingle with gentiles not to say preach the gospel among them. Paul choose the narrow path hence refering to the  OT  in the book of Psalm 18:49 "For this, I will praise you among the Gentiles; I will sing praises to your name"

However we also have to remember that Apostle Paul also took a very different approach when the Gospel itself was at stake. In Galatians, for example, Paul confronts false teaching about the gospel by severerly castigating the false teachers (Galatians 1:6- "I am shocked that you are turning away so soon from God, who called you to himself through the loving mercy of Christ. You are following a different way that PRETENDS to be the Good News" and he also warned that adopting false teaching will alienate them from christ. Galatians 5:4 "For if you are trying to make yourself right by keeping the Law, you have been cut off from Christ! You have fallen away from God's grace." Paul said it is faith in Christ that provides access to all God's favour and grace. ----Gal 5:6 "and this faith is expressed by exercising LOVE towards others" -- Romans 13:10 "Love does no wrong to others, so love fulfills the requirements of God's law.

In our day, we have to be careful about what we tolerate and accomodate, and we need to be equally be careful about what we decide is worthy of confrontation. Believers need to consider carefully (an expression of love) the different issues they confront in their association with other believers at all times.

If the basic truth of the Good News is not violated, we should not quarrel or be divided over such issues. Other issues, however that strike at the heart of the message of the Gospel, in these cases a christian need to take a stand and be faithful to the Good News, and to Christ.

CONCLUSION
The way Apostle Paul himself dealt with a variety of issues in his own time can serve as a guide for dealing with conflicts and controversies in our time. The same can be said of true mature christians who fight the good fight.

God bless