During one of its Hope for Houston services on Sunday, Osteen told the congregation that there was "so much misinformation that he wanted to clarify a few things."
After a massive round of applause from the congregation, he said: "This building flooded in 2001, when the Rockets were still playing basketball here.
"It was over five feet of water in this lower bowl. Knowing that, when we took possession, we installed large flood gates around the building.
"The hurricane floodwater came within a foot or two of reaching the new gates and flooding the building again. Without those floodgates, we wouldn't be here today."
Osteen added that the water started to recede between late Sunday and early Monday and the church did not feel it was safe to take hurricane victims in until Tuesday.
"If we had opened the building earlier and someone was injured and perhaps it flooded and people lost their lives, that would have been a whole different story," he told his church members.
He said he was "at peace with taking the heat for being precautious" but didn't want to "take the heat for being foolish".
"It's easy for people to take judgement from a distance without having all the information," he said.
"Some people that don't know the facts and don't want to know the facts will continue to try and stir things up."
Osteen said that he was at peace with his decision. He claimed that people who took to social media and slammed the church for not opening its door to victims right after the hurricane would love to discredit the ministry and attack what the church stands for which is " faith, hope and love."
Joel Osteen and Lakewood Church received a wave of criticism online when the deadly Hurricane Harvey struck Texas last week.
People accused the church of keeping its 16,000 seat building closed to vulnerable victims.