Here's an activity. David was imperfect but his worship was heart-felt honest expression, and he feared God.He was a man after God's heart. God interacted with him and responded to him. He responded to God.
Take a class of kids who old enough and comfortable with reading and writing and able to rethink ideas and put them in their own words.
Ask some questions - Who is the Psalm written for? Psalms are written as worship - for God. But some are for God's ears only. Some are written to encourage your own soul. Some to encourage or draw in the people around you to worship and praise. What else can you discover about who the Psalm is for? When would someone use a prayer or praise like this? How would they be feeling? Sometimes they fit into David's story and you can tell what was going on with him and what he was feeling. Some of the Psalms aren't even David's.
Give them a Psalm to rewrite in their own words as a very honest prayer or as praise - an expression of personal worship to the Lord - like David did. Don't worry about accurate rendition of the text. With a listening heart, look for David's heart-rending honesty. If they're mostly the same, listening to all of them would get boring. On the other hand, if they're quite different, it might be interesting to listen to all of them.You can post them on the wall or you can let each of the kids pick a partner for the first read. You pick a partner or let them split into groups of three for the 2nd or 3rd read. New listeners each time.And nobody comments. Just listen. They're all using the same Psalm.
Here's one: from Psalm 15
Lord, who lives in Your house?
That house on a hill - a holy hill?
How 'bout me?
I'm not the kid who never gets blamed.
The one who always does the right thing
Sometimes I lie
Sometimes I gossip
(or slight someone)
Sometimes I bad-mouth people
Sometimes I hurt people
People like me don't live in Your house.
But I want to.
Teach me to despise vile people
[I thought God loved everyone and just hated their sin?]
Teach me to honor those who fear You
[even when they aren't perfect]
Teach me to keep an oath until it hurts
[even when everyone else breaks their word]
Teach me how to lend without doing it to earn interest,
without expecting to profit from giving or lending
to give without expecting anything in return
If someone tries to hire me or convince me
to wrong someone
who doesn't deserve it
I'll say "no."
Maybe I can be someone who lives in Your house.
The people who live in Your house are unshakeable.
If I can live in Your house, I'll be unshakable, too.