All perfect praise be to Allaah, the Lord of the worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and messenger.
The phrase “convergence of sects” is too general. If you mean convergence between Ahlus-Sunnah Wal-Jamaa'ah and innovators in religion, we see that this is impossible. Some people who work in the field of Da’wah reformers tried to bring together Ahlus-Sunnah Wal-Jamaa'ah and some sects. However, it proved to be impossible. Anyone who knows the truth about many of the sects which claim affiliation to Islam undoubtedly realizes their falsehood, because of their incorrect beliefs about the companions of the Prophet, sallallaahu ‘alayhi wa sallam, and their disagreement with Ahlus-Sunnah Wal-Jamaa'ah on many fundamental areas of belief.
However, if you mean the convergence of schools of jurisprudence, then such convergence is undoubtedly good Da‘wah as long as it is undertaken by skilled men in this field. Unity results in goodness and blessing. Allaah urges us to hold fast to His rope when He Says (what means): {And hold firmly to the rope of Allaah all together and do not become divided.} [Quran 3:103]