The story of Jesus Christ's prayer in the Garden of gethsemane and his betrayal by his disciple Judas Iscariot discusses heavy themes that can be difficult to convey to young children. You can use life application activities and object lessons to help little minds understand big concepts.
Ask a volunteer to stand next to you in front of the class. Tell the class the different reasons why Jesus was sad in the Garden of gethsemane. For example, his friends fell asleep when he asked them to pray, and he knew he was going to be arrested and that Judas had betrayed him. As you describe each reason, give the volunteer a heavy book to hold, illustrating how Jesus was literally weighed down by sadness. Tell how God sent an angel to strengthen Jesus, and take the books from the child's arms. Do the exercise again, except when you give the books to the volunteer, describe struggles children face, such as "a friend laughs at you" or "your sibling is mean to you." Tell them Jesus knows what it's like to be sad, and he can send help.
Give each child two pretzels in the classic "folded arm" shape. Let them eat one pretzel, and ask them to look at the shape of the other pretzel. Tell them there's a legend that says monks used to give pretzels as rewards for children who memorised their prayers. The twisted shape looks like the arms of a child praying. Tell them the story of Jesus praying in the Garden of gethsemane and how his stomach was tied in knots, just like a pretzel. Follow up this activity by forming a human knot, in which children stand in a circle and hold hands with two different people not standing next to them. Let them try to untangle themselves.
Modern Day Betrayal
Have children each write one way someone has disappointed them on a scrap piece of paper. Collect the papers and read them out loud. Say, "Sometimes people disappoint us. How should we treat those people?" Let students answer, and then tell them how Judas betrayed Jesus. Tell them how Jesus still loved Judas despite what he did, and that people should love others who hurt them. Read the papers again, and, as a class, brainstorm how children can respond to each situation. For example, if a friend tells a lie about you, say, "I don't like what you did, but I forgive you. Can we still be friends?"
Big Picture Puzzles
Pass one puzzle piece around to each student. Ask the class to tell you, based on that single piece, what the whole puzzle looks like. Children will likely say it's an impossible task. Next, tell the story of how Jesus asked God for relief in the Garden of gethsemane. Jesus didn't want to die, but he prayed that God's will be done. Tell children that God can see the whole puzzle, but people can only see one tiny piece. Sometimes after bad things happen, like when they have to do chores, they may realise later that it was good for them. That's why people should always pray for God's will in their lives---just like Jesus did.