Both were God's way. God told Noah to build the ark. When the ark was finished, God told Noah and his family "to come thou into the ark .." in Genesis 7 KJV. That applies only if God is already inside. There was only 1 door, 1 entrance into the ark just as Jesus is the door, the way - the only way. When all had entered the ark, God shut the door, sealing them in, holding them secure through the storm. It is the... blueprint, the forerunner for the new covenant. The Old Testament shows us, among many other things, what His plan of redemption was from the start. And it's laid out beautifully all along the way.
