I'll give it a shot, Mandy. Maybe I can help. Firstly I'm wondering who "your teens" are. Are they your children? Your "every night" goal implies that they are.
The scriptures you cited, for starters, are difficult and not much attractive to teens. The bottom line message of the scriptures you listed is: You must always be ready because your time of judgement will come when you least expect it.
To a teen, and to adults too, that's a pretty much impossible thing to do. Is this our bottom-line lesson from the Noah flod story? Your selected New Testament scripture (Matthew 24:37-44)
seems to indicate that it is. If I were a teen I might want to quit this endeavor right at the get go.
Oh! Another question I must ask: Are you a Bible literalist? I'm not. Do you want to teach your teens an inflexible, absolute, God's whole and infallible literal word in the Bible? If that be the case scrap everything I suggest from here on out. I can't help.
I think your teens will appreciate learning the wonderful and fascinating stories about people in the Bible. They may even get excited about some of them. The people stories can be treated as human history or legend and some of them as mythology, or with a smattering of each. I don't recommend trying to match the old testament to the new. They are separate times and they portray different human perceptions of God. The Bible describes to us how those perceptions have changed. The Bible describes how our perceptions evoloved to what Christians understand -- of God -- today.
What do you hope for your teens to get from you devotions and Bible study? Faith? Values? Increased awareness and appreciation of God? Would you like them to learn that God is their friend who will always be there for them in future difficult times?
Do you want them to learn to fear God and to fear their judgement day?
Both? Which do you think will work best for them as their lives progress? Faith, aware and appreciation -- or fear? Personally, I don't think fear works well at all. Personally, I feel like God is my buddy. We visit like we're buddies. I try to live my life in ways that I think will please my BIG buddy who I have sometimes called the "Big guy."
So, what can I recommend?
What do you want to teach your teens? That's a good place to start. Here's a link to a web-page I wrote that started me on a wonderful learning journey: Explore faith with me
. Is this something like what you hope for your teens?
What about ways that Bible stories sometimes conflict with what we believe of God? Who is this God guy?
This one's in two parts. Then we take a look at God as "our Father."
Then we might start with a people story out of the book of Genesis about faith, accomplishment and forgivenss in contest with betrayal and adversity: the story of Joseph in two parts.
Check it out, Mandy. You will find links to more that may help you. Let me know how it works for you -- and if this is something suitable for your teens. Can they learn something from Joseph, do they appreciate him and does this help them to appreciate God?
Sincerely, George H. Birkett