I recently started watching NCIS, a television drama now in its 16th season. In the series, a team of special agents from the Naval Criminal Investigative Service investigate crimes involving the U.S. Navy and Marine Corps. The team is led by Jethro Gibbs, a no-nonsense former Marine who follows a series of 51 tenets known as Gibbs’ Rules.

Gibbs’ Rules guide both his professional and personal life. They range from practical principles of behavior — “Never let suspects stay together” and

“Always wear gloves to a crime scene” — to axioms like “Sometimes you’re wrong,” “Clean up your messes” and “Bend the line, don’t break it.”

While we may not be as purposeful as Gibbs in numbering our rules, we all have them. They can range from cultural tenets to principles we’ve picked up along the way or those we’ve been taught by experience and those around us. Some we are conscious of. Others we operate by unconsciously.

Our rules shape our behavior, so it’s important to be aware of them — and to know where they came from.

That makes me think about Jesus and how he placed all his “rules” under two big ones.

When Jesus is asked which is the most important of all commandments, he quotes two sections of the Torah, the first in Deut. 6:4-9 and the latter in Lev. 19:18: “ ‘Hear, O Israel, the Lord our God, the Lord is one. Love the Lord your God with all your heart and with all your soul and with all your mind and with all your strength.’ The second is this: ‘Love your neighbor as yourself.’ There is no commandment greater than these” (Mark 12:29-31).

In Jesus Creed, New Testament scholar Scot McKnight points out that Jesus is transforming the Old Testament Shema — “the quintessential expression of the most fundamental belief and commitment of Judaism” — located in the Deuter­onomy passage by adding the verse from Leviticus. “For Jesus, love of God and love of others is core,” says McKnight. These two commandments become his followers’ spiritual center.

What does it mean to love God? According to Jesus, says McKnight, “one loves God by following Jesus” — and “to follow Jesus as an act of love means to trust him.” That trust is expressed through a transforming relationship, where we abide in him.

By adding the verse from Leviticus, Jesus allows the surrounding text to inform what loving others looks like. “Love in the book of Moses,” Mc­Knight says, “means respecting parents, providing for the poor, protecting private property, honoring one’s word, caring for the physically challenged, seeking justice for the powerless, living in sexual purity, showing love for one’s enemies — and lots more!”

When Jesus is asked to define “neighbor,” he tells the parable of the Good Samaritan. “Loving God properly always means that we will tend to those in need,” says McKnight, who goes on to quote Francis Schaeffer’s The Mark of a Christian: “Love — and the unity it attests to — is the mark Christ gave Christians to wear before the world. Only with this mark may the world know that Christians are indeed Christians and that Jesus was sent by the Father.”

If we are followers of Jesus, then, “whatever [we] do throughout the day,” says McKnight, “is to be shaped by loving God and loving others.”

Love God, love others: Rules to live by that not only have the potential to change us but also the world.

Carmen Andres, a former editor of the Mennonite Brethren magazine Christian Leader, lives in Alexandria, Va.