Thanks for your question.
God commanded Adam to be fruitful and multiply. Having babies was intended to be based on a stable and happy marriage between two partners. Note, Jesus says that in the beginning God intended monogamy ("two shall become one flesh”). Polygamy (more than one wife at the same time) is wrong. If a speedy populating of the earth had been the sole objective, God would have allowed many wives. Polygamy was tolerated in Old Testament times, but in the New Testament one man to one wife is the rule (see 1 Timothy 3 v2, 12).
Regarding Christian Marriage, please read the following information available on the website:
Regarding going to hell, please read the following information available on the website:
I hope you have found that helpful.
God bless and keep you,