"Israel created Hamas."
Israel had nothing to do with the creation of Hamas. The The organization grew out of the ideology and practice of the Islamic fundamentalist Muslim Brotherhood movement that arose in Egypt in the 1920s.
Hamas was legally registered in Israel in 1978 as an Islamic Association by Sheikh Ahmad Yassin. Initially, the organization engaged primarily in social welfare activities and soon developed a reputation for improving the lives of Palestinians, particularly the refugees in the Gaza Strip.
Though Hamas was committed from the outset to destroying Israel, it took the position that this was a goal for the future, and that the more immediate focus should be on winning the hearts and minds of the people through its charitable and educational activities. Its funding came primarily from Jordan and Saudi Arabia.
The PLO was convinced that Israel was helping Hamas in the hope of triggering a civil war. Since Hamas did not engage in terror at first, Israel did not see it as a serious short-term threat, and some Israelis believed the rise of fundamentalism in Gaza would have the beneficial impact of weakening the PLO, and this is what ultimately happened.
Hamas certainly didn't believe it was being supported by Israel. As early as February 1988, the group put out a primer on how its members should behave if confronted by the Shin Bet. Several more instructional documents were distributed by Hamas to teach followers how to confront the Israelis and maintain secrecy.
Israel's assistance was more passive than active; that is, it did not interfere with Hamas activities or prevent funds from flowing into the organization from abroad. Israel also may have provided some funding to allow its security forces to infiltrate the organization. Meanwhile, Jordan was actively helping Hamas, with the aim of undermining the PLO and strengthening Jordanian influence in the territories.
Though some Israelis were very concerned about Hamas before rioting began in December 1987, Israel was reluctant to interfere with an Islamic organization, fearing that it might trigger charges of violating the Palestinians' freedom of religion. It was not until early in the intifada, when Hamas became actively involved in the violence, that the group began to be viewed as a potentially greater threat than the PLO. The turning point occurred in the summer of 1988 when Israel learned that Hamas was stockpiling arms to build an underground force and Hamas issued its covenant calling for the destruction of Israel. At this point it became clear that Hamas was not going to put off its jihad to liberate Palestine and was shifting its emphasis from charitable and educational activity to terrorism. Israel then began to crack down on Hamas and wiped out its entire command structure. Hamas has been waging a terror war against Israel ever since.