Ephesians 6:18
…praying at all times in the Spirit, with all prayer and supplication. To that end, keep alert with all perseverance, making supplication for all the saints…
To pray intercessory prayer is to have interest and investment in other peoples’ lives. Every saint—every Christian—needs prayer. Thus, you and I should be praying every day. If we are not, we are failing our Christian duty. Go ahead and point a finger at me, “Do you pray every day?” No, I do not, for I am a sinner, but I won’t hide from my hypocrisy by pointing the finger at someone else. I’m already aware of my failure in this Christian duty, hence my proactive decision to pray before every meal and every night, though I often forget. Lord, forgive me!
You do not need to adopt my practice, but you do need to formulate some kind of prayerful practice, especially one that is intercessory. Why does God command us to pray for one another? In short, because we are part of the family of God and His saints—His children—and we never stop needing our Father.
Some brothers and sisters might not know any better to pray for themselves; thus, we intercede on their behalf and pray for their needs they haven’t recognised. Some brothers and sisters might be unrepentant; thus, we pray the Holy Spirit do His work and convict them in their sin and bring them to repentance and to trust in Christ’s absolution.
Other brothers and sisters might already be praying and in weakness, due to stress and despair, might need our strength and encouragement; thus, we pray for them to lift up their hearts that their prayers might be answered.
Intercessory prayer is one way in which God’s family takes care of one another. See to it, then, that you recognise your brothers’ and sisters’ needs and intercede for them as necessary.
The Lutheran Column 