Differences are a part of life. A divergence of views and behaviour arises between people for a variety of reasons. Just as differences occur among unbelievers and apostates similarly differences occur between sincere and pious people. But even if differences cannot be prevented, that is no reason, for any individual to indulge in negative behaviour. It should be borne in mind that despite differences, positive behaviour is both a possibility and a necessity.
Regarding a person as being wrong about everything just because he holds different opinions and calling him a hypocrite, bad intentioned and insincere are entirely un-Islamic reactions. The true believer looks at the issue of difference as a matter of intentions, and limits any ensuing dissension to the sphere of its origin. He never allows matters to escalate.
Severing relationships due to differences is not in accordance with the spirit of Islam. Mutual relationships should be maintained while continuing serious discussion of contentious issues. Not greeting the person with whom one has differences or refusing to meet such a person is highly improper.
In this present world everything is designed to put man to the test. Differences also serve this purpose. Man ought to be extremely cautious, particularly at moments of contention. He should continuously strive to be tolerant lest he show some improper reaction, which would be displeasing to God.
Remaining impartial in the face of differences is indeed a difficult task. But its reward too is great. Every right act is treated as an act of worship in Islam; it is therefore an act of superior worship when, in spite of controversies one keeps one's heart free of enmity and vengefulness and adheres strictly to the path of justice.
The emergence of difference is not in itself a bad thing. What is bad is that at the time of arising differences the individuals concerned do not rise to the occasion. They fail miserably in the divine test. Remaining within the confines of taqwa (fear of God) at times of conflict is a great Islamic act, and crossing the boundaries at such moments is an un-Islamic act of the worst degree.