Referring to Congress' criticism of the Gujarat chief minister, he said, "Modi does not require any certificate from Congress whether he is secular or non-secular."
Ramdev said Modi's "puppy" remark was misinterpreted and advised him to be cautious as his statements were taken in a negative sense.
"Modi has credibility while the BJP needs to bring lot of change in its character," he said.
Ramdev said he would support any leader who vowed to bring back black money, end corruption and bring a change in the present system.
He said he had met both Modi and Congress Vice President Rahul Gandhi on these issues.
"I am behind Modi as he is capable of bringing back black money, ending corruption and bringing a change in the present system," he said.
When asked whether Ram temple should be an election issue, he said, "Ram is a symbol of national honour of the country. I don't think there should be a debate on the issue of building Ram temple."
Ramdev asserted that corrupt persons in the country should be given stringent life imprisonment and their properties must be attached by the government.