In my conversations with non-Catholic Christians, I find that one of the most difficult doctrines to discuss is our relationship with others in the Body of Christ. Such a double irony, right? We struggle with relating to each other because we struggle with how Jesus teaches us to relate to each other.
This was one of my biggest bugaboos on my way into the Church as well. After all, when we talk about prayer, we touch on the secret sanctuary of our thoughts. It's hard enough to conceive of God being able to read everything that is written there before we even have the courage to dip in and pick out our worries, fears, needs, pain, exultation, and joys, hold these open to God and start to lay them bare to Him. How in the world do other mere human beings get in on this conversation? Are they omniscient, like Him, to hear my prayers and read my secred thoughts? Are they substitutes for God? Do we go to them because we are afraid of Him, or we aren't important enough to trouble Him? Are saints put in charge of specialties, like the Greek and Roman gods? Is this a syncretism carryover? Doesn't the Bible clearly say that there is one mediator between God and men, the man Christ Jesus? If Jesus is the one mediator, doesn't that mean that anyone else going to God on our behalf is unbiblical?
So, let's start with that last point. The eternal Son of God who took on flesh in Jesus Christ is the only way that we come back into relationship with the Blessed Trinity, a relationship broken historically by the Fall. He is the only one who has taken on the penalty for our sins and has now opened heaven for us and welcomes us back into union with the Blessed Trinity.
But the mediation of the Son of God is not the same thing as intercessory prayer, and that is illustrated all over the Bible, where we are commanded and taught to pray for each other. "Pray for those who persecute you," for example, from Jesus' own lips. And oodles of other references.
St. Paul also teaches us that in the Body of Christ, the eye cannot say to the hand "I do not need you." All of the parts are made to belong to one another.
We don't cease to belong to the Body of Christ when we die. In fact, death leads to our glory in heaven, where after thorough purification from sin, we enter the Most Holy Place, where Jesus Himself is. There, union with God is no longer mediated by faith. We are known fully, even as we are fully known. Union is complete, to whatever degree our creation has been filled by Him.
When we go to confession, one of the aspects of sin that we have to grapple with is that no sin is private, even when it is completely secret. Choices in favor of not-God ripple out from us. We seek reconciliation to heal not only our own hearts and our relationship with God, but also the relationship with the Body of Christ.
So when I pray, you bet your booties I seek the intercession of those already in heaven. The way I experience it is like this: My soul comes before the Lord, in the majestic splendor of His glory, His heaven. (This actually exists, by his grace, within my soul.) As I pour out my heart to Him, praising Him for His grace and mercy and favor and soaking in His love, I also acknowledge the help that I need to live from this place. After I'm done praying, I need to not snap back into me being Lord and Ruler of all, Caller of all shots, Namer of good and bad, right and wrong. I soak in Reality, and I need to live out of that place of peace, even in the face of suffering, pain, responsibility, work, and all the rest. I call upon saints that I have gotten to know, who have run the race and fought the fight, and by God's grace have won the crown. They have learned to do what I am now wanting to do. Kneeling before the Lord, I ask them now to come in the Spirit and "lay their hands on me," invoking the Holy Spirit through their human love for me to send me that which I need, especially what they can see that I need that I cannot.
I trust people on earth to do this for me. Or rather, I trust that when my friends obey God's command to intercede, that He will answer. I trust that God will answer as my friends in heaven ask Him, too. How can they hear me? I am speaking to the Head, and they are his members. I don't know if I can find this line in the Catechism, but if Jesus is the head, perhaps the Holy Spirit is the central nervous system. The same Holy Spirit that bids me call out Abba, Father, that bids me draw near Jesus, fills them and compels them. We can't really imagine what the communion of heaven is like, but it is perfect love both for God and for neighbor, because that's how love works.
The impoverishment of the Christian faith leaves out the glory God gives us in being secondary causes, cooperators with His grace, agents of His love, fully alive in His Spirit, bonded intimately with Him, sharing His own loves and concerns for those still in the race.