The novena is a prayer that is done for 9 days although the bible never mentioned anything about novena. But this prayer is just like a devotion we put in to worship God. In Scripture, believers are encouraged to pray continually and with perseverance. For example, the disciples waited in prayer between Jesus’ ascension and the coming of the Holy Spirit, which some see as a foundation for extended periods of focused prayer.
“men ought always to pray, and not to faint” (Luke 18:1)
The bible never tell us to have a specific prayer for complete 9 days. The bible tells us to always come to God with a sincere heart and be serious whenever we are praying. Jesus tells us never to be repetitive in our prayers, but always go straight to the point. From a biblical perspective, a novena can be meaningful if it encourages faith and devotion, but it should not replace a genuine, personal relationship with God or be seen as a guaranteed method for receiving answers.