Each person is different and the lives we lead are not the same. Each life should have meaning but that meaning differs from person to person even though the experience or underlying precepts are similar.
A meaningful life has a purpose. It keeps us excited every day. It is knowing that you are making a difference in your world and other people's lives. It is knowing that your life is a vehicle for change and improvement. It is using your knowledge, talents, and skills that you use for the benefit of others and for things you care about. It is knowing that you are making things better.
Moses at 80, found meaning in a Voice calling out to him from a burning bush.
Elijah found meaning by confronting the heresy plaguing Israel in the form of Ahab and Jezebel.
Nehemiah, the king's cup-bearer, saw meaning in reaching out to protect his people.
Daniel found meaning in a life of prayer.
David found meaning in confronting the enemies of Israel.
Paul was flogged, stoned, cursed, chased, and shipwrecked but each day he would awake with one purpose, to go out into the world to spread the gospel of Jesus Christ. He often put his body on the line to accomplish his purpose.