What is the most foundational requirement for ordained leadership in the church?

It is deep, mutual love and fellowship among the leaders themselves.

If this is not the case, no quantity or quality of shepherding proficiency, or discipleship prowess, or ecclesial acumen, or liturgical expertise, or hermeneutical rigor, or counseling nurturance, or stewardship shrewdness, or homiletic mastery, or catechetical adroitness, or pastoral aptitude, or exegetical agility, etc. will make a church healthy, or keep it aligned with Jesus of Nazareth for the long haul.

The Ordination Mandate: Friendship First, Work Second
When Jesus officially appoints and ordains His apostles (e.g. Mark 3:14), He “appoints them, designating them apostles, that they might be with Him and that He might send them out to preach.”
*Notice the sequence: before any administrative work, preaching, or sheep-tending is assigned, the mandate is relational presence—being together with Him and with one another.
Jesus reinforces this priority on the night before His death, changing their official status from subordinates to intimate friends: “No longer do I call you servants… but I have called you friends…” (John 15:15). Before they are leaders of the church (and the most essential dimension of their leadership of the church – is that), they are bonded as a circle of genuine friends.

Moreover, the ordained and installed leaders of the church ARE NOT the most competent, enlightened, influential, and/or impactful members of the church. Throughout the Gospels, the apostles are consistently and emphatically described as immature and puerile. For example, they squabble over status (Mark 9:34), lack faith (Mark 4:40), push away people in need (Luke 18:15), and flee during crisis (Mark 14:50).

By contrast, non-ordained, unappointed figures consistently demonstrate superior spiritual maturity and impact. For instance… the Roman Centurion (Luke 7); the Syrophoenician Woman (Mark 7); Mary of Bethany (John 12), the Samaritan Woman (John 4): and small children (Matthew 18).
If official leadership were primarily about maturity, insight, counseling compassion, shepherding competence, etc. Jesus chose the wrong group. His choice highlights that formal leadership is not about personal competence, but about a shared relational community.

The Core Metric: Mutual Love as the Primary Shepherd Tool
When Jesus provides His defining directive to the ordained group, He does not focus on church organizational models, preaching strategy, or administrative oversight. Instead, He commands mutual love as their primary identifier: “A new commandment I give to you, that you love one another: just as I have loved you, you also are to love one another. By this all people will know that you are my disciples, if you have love for one another.” — John 13:34–35

Jesus explicitly states that the world—and by extension, the flock—will recognize true leadership not by how efficiently the leaders manage the church, but by how deeply the leaders love each other. The health of the flock is a direct byproduct of the relational unity of its elders.

Perhaps one of the most definitive and dramatic scenes that solidifies this is the re-commissioning of Peter in John 21, Jesus is aggressively driving at the ultimate prerequisite for elder ministry. The MAIN question throughout this interaction between Jesus and Peter is, “Do you love Me?” Jesus does not ask Peter about his management capabilities, doctrinal efficiency, his counseling competency, or any strategic plans for the church. The chief qualification for shepherding the flock is love.

If a session functions as an elite administrative, shepherding, counseling, discipleship body whose members do not genuinely love one another (sincerely enjoying deep and abiding friendship with one another), then they contradict the most emphatic and essential mandate of Jesus; and no matter how well they shepherd, counsel, and disciple the flock, they will inevitably corrupt and clapperclaw the church if they do not primarily enjoy friendship and genuine fondness for one another. The congregation is best protected, fed, and led when the elders embody the trinitarian model of fellowship, where the overflow of their brotherly love creates a safe, healthy environment for the entire flock.