I'm not saying they knew everything about the coming death and resurrection of Christ but that they required faith (more faith because they didn't understand the details like us), to be saved. I'm saying both old and new testiment people needed faith to be saved and God has not changed His requirements of salvation.
Heb 11.4 By faith Abel offered unto God a more excellent sacrifice than Cain, by which he obtained witness that he was righteous, God testifying of his gifts: and by it he being dead yet speaketh. note
5 By faith Enoch was translated that he should not see death; and was not found, because God had translated him: for before his translation he had this testimony, that he pleased God.
6 But without faith it is impossible to please him: for he that cometh to God must believe that he is, and that he is a rewarder of them that diligently seek him.....
13 These all died in faith, not having received the promises, but having seen them afar off, and were persuaded of them, and embraced them, and confessed that they were strangers and pilgrims on the earth.