A Weak Body and a Strong God

Order of Service

• Scripture Reading & Sermon — Psalm 71
• Pastoral Prayer

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Sermon Title: A Weak Body and a Strong God

Scripture: Psalm 71

I. A Weak Body and a Strong God

A. David's physical vitality is waning in old age, yet he leans on God's strength as his own diminishes

• Language of God as rock and fortress appears throughout: verses 3, 7
• Contrast with David's condition in verse 9: strength is spent, enemies still press in

B. The troubles of a fallen world do not diminish with age; they become harder to bear

1. Illustration (Boice): a cantankerous elderly mother continues to cause difficulty for her caretaker daughter — problems do not simply resolve with age
2. Old age heightens the sense of helplessness before ongoing trials

C. God's sustaining grace is displayed most powerfully through weakness

• 2 Corinthians 12:9 — "My grace is sufficient for you, for my power is made perfect in weakness"
• Weakness is not merely a problem to overcome; it is an instrument through which God magnifies his glory
• The Lord's sustaining grace when we cannot sustain ourselves is a primary means by which God displays his power to us and to a watching world

II. A Weak Body and a Strong Faith

A. David traces God's faithfulness from before birth through old age (Psalm 71:5–6)

1. God upheld him in the womb before he could consciously trust — a comfort for those whose mental faculties are fading
2. As David enters old age with weakening faculties, he rests in the God who sustained him even as a helpless infant

B. David mentions his youth twice (verses 5 and 17)

1. His faith was displayed early — slaying Goliath, faithful as a young shepherd
2. A message to the young: walking with the Lord in youth is an investment in one's latter years
3. However, this is not limited to those with faithful youth — even wandering years fall under God's providential care leading sinners to the Savior
4. David's own failures (sin with Bathsheba, conspiracy against Uriah) show the psalm is not about David's faithfulness but about God's

C. In verse 15, David looks beyond his personal testimony to the redemptive acts of God in Israel's history

1. The Exodus and Red Sea event serve as monuments of God's redemptive grace
2. 1 Corinthians 10 — these things were written down for the church living in the last days
3. The Red Sea event is the church's event; grand redemptive acts recorded in Scripture are meant to garner confidence in days of weakness
4. The psalmist "owns" these acts though he was not a direct participant — the God who parted the sea is the same God who acts for his people now

III. A Weak Body and a Strong Testimony

A. Verse 18 is a key verse for all believers regardless of age

• "So even to old age and gray hairs, oh God, do not forsake me until I proclaim your might to another generation"
• Echoes Paul in Philippians 1 — as long as there is breath, there is a calling to proclaim the excellencies of the gospel

B. The great temptation of weakening strength is to give up and disengage

1. There are appropriate things to hand off to the next generation
2. But proclaiming God's goodness and faithfulness is the one thing a believer should never declare themselves too old to do — even to a final whisper

C. The church is one generation away from extinction if the gray hairs do not pass down what they have learned

1. Contemporary culture champions youth and pressures the elderly to act young — a devastating trend for the people of God
2. Gray hairs are to own their age and cry out to God so they can pass down his steadfast love to the next generation

D. David's eyes are set on resurrection life (Psalm 71:20)

1. "You will revive me again; from the depths of the earth you will bring me up again"
2. Verse 23 — his redeemed soul will rejoice in God
3. These words are ultimately placed on the lips of David's greater Son, Jesus Christ — surrounded by enemies, in mental and physical anguish on the cross, raised from the depths of the earth and exalted to God's right hand

E. Reading Psalm 71 through Christ brings deeper comfort

1. The old and weak also need encouragement — there is real bodily and mental weakness, and pressure on the elderly to project perfect faith is misplaced
2. Christ becomes the wise elder who draws all of us, regardless of age, into the comfort of God's goodness and faithfulness
3. Christ knew the realities of this psalm more fully than any — crying out "My God, my God, why have you forsaken me?" (Psalm 22:1) — and conquered
4. Because Psalm 71 is first Christ's psalm, it becomes, in and through him, our song of praise, thanksgiving, and hope