Same-sex marriage was backed by the Scottish Parliament last night, when it voted on the general principles of the Bill for the first time.
But some MSPs raised serious concerns about the legislation, which was passed to the next stage by 98 votes to 15.
Nationalist MSP John Mason said he opposed the Bill because marriage is between a man and a woman, and there is a lack of safeguards for those who disagree.
He also said: “Parliament is not reflecting public opinion on this issue.”
“It can be argued whether those supporting or opposing the bill have the greater numbers on their side, but there is certainly not the overwhelming support outside this place that there seems to be inside.”
Labour MSP Elaine Smith said the proposals fail to protect free speech for pro-traditional marriage supporters.
She said: “Since indicating that I did not intend to support the redefinition of marriage, my religion’s been disparaged, I’ve been branded homophobic and bigoted, I’ve been likened to the Ku Klux Klan and it was suggested that I be burnt at the stake as a witch.”
And Tory MSP Alex Johnstone said gay marriage is the “wrong priority” for the Scottish Parliament.
He said: “During my lifetime, I have seen society beginning to fall apart.
“That’s why I would argue that one of the priorities of this parliament should be to strengthen families, to find ways to reinforce marriage and to make sure that we reverse the trends of half-a-century and more, in order to gain that stability.”
The Marriage and Civil Partnership (Scotland) Bill will now progress to stage two, when amendments will be considered by a committee.
Speaking for the Scottish government, Health Secretary Alex Neil said he believes the legislation will allow all people who love each other to have the “same opportunity as each other in Scotland” to have their marriage recognised by law.
MSPs were allowed a free vote on the Bill.