It’s no small miracle to have a strong heart. Hearts stutter and fail by arrhythmic drumbeats every day. I’ve been to that hospital wing, sat by that bedside. 

“They glued me back together,” a man explained to me once, tapping his sternum after an open-heart procedure. “It’s superglue.”

In what’s likely the most ancient Christian text we have, Paul writes a blessing-prayer to the church in Thessalonica: May the Lord “strengthen your hearts in holiness” (1 Thessalonians 3:13). It’s a prayer that the Lord make our identity firm in word and worship.

At the end of chapter 3, the Apostle wraps up a span of greetings and thanksgivings. He writes to a church he knows and has nurtured. Acts 17 records him and Silas planting the first seedlings of the gospel in Thessalonica. The church immediately grew — and walked into the buzz saw. “These people who have been turning the world upside down have come here also,” the Establishment Men complain in Acts 17:6.

And turn the world upside down they did. Paul and the first Christians believed that Christ is the risen Lord, for real and forever, and so the old gods and caesars are thrown down, the old covenant fulfilled and flipped open to all. 

First Thessalonians is a letter written back to a church that has taken the first, brave steps of faith. Paul wants them to know that while he has moved on in his missionary journey, he hasn’t forgotten them. 

Verse 9: “How can we thank God enough for you?” 

Verse 10: “Night and day we pray most earnestly” to see you again. 

The whole thing resolves in benediction: May God “direct our way to you,” make you “increase and abound in love” and “strengthen your hearts in holiness” (verses 11-13).

The “heart” Paul prays for is the biblical word for who we are at our human core. It’s our identity. The Lord “looks at the heart”: the seat of desire, wisdom and will (1 Samuel 16:7; Psalm 20:4 and 90:12; Proverbs 4:23).

The word Paul uses for “strength­en” means “sustain,” “uphold” or “steady” (Genesis 27:37; Psalm 51:14 and 112:8). 

In the New Testament, Peter writes the churches to help them be “established in the truth” (2 Peter 1:12). 

Acts 18:23 describes Paul passing among the churches of Galatia and ­Phrygia “strengthening all the disciples” through his teaching and presence.

Our hearts are made strong when we true them to the gospel. Paul mentions the Thessalonians’ faith five times in this chapter and describes how he earlier sent Timothy as a teacher “to strengthen and encourage you for the sake of your faith” (3:2). 

Strong hearts have God’s Word hidden in them (Psalm 119:11). The truth of God’s word becomes the undergirding reality of our lives. 

Paul envisions a people made strong-hearted through worship of the triune God. He crafts this passage in God’s trinitarian image: God the Father, the Lord Spirit and the Lord Jesus (verses 11-13). 

We’re called into our identity through baptism in the threefold name of God. We become more truly ourselves through confession, praise, hearing the word, sharing at the table and being sent on a mission. 

When a people’s heart is strong, they can walk through hard things — ­confusions within and persecutions that shake them from without (3:3). Blood and holy fire beat in their veins. 

The world is a landslide that can break and bury us. But God gives strength — a superglue grace that holds our hearts together in his love.