Islam

Tawhid — the absolute, undivided oneness of God, who has no son and no partner. The Trinity is rejected as blasphemy (shirk), the one unforgivable sin.

Their basis
Quran 112 (Al-Ikhlas): 'He is God, One... He begets not, nor is He begotten.' Quran 4:171 warns 'Say not Three'; 5:73 condemns those who say God is one of three. Zeal to guard God's transcendent oneness and never associate a creature with the Creator.

Scripture answers
Scripture affirms one God (Deut 6:4) — Christians are not tritheists — but that one God eternally exists as Father, Son, and Spirit. Jesus is called God (John 1:1,14), receives worship as 'my Lord and my God' (John 20:28), says 'I and the Father are one' (John 10:30) and 'before Abraham was, I am' (John 8:58), and in Him 'the whole fullness of deity dwells bodily' (Col 2:9). The one name into which we are baptized is threefold (Matt 28:19).

Deuteronomy 6:4John 1:1John 1:14John 10:30John 20:28John 8:58Colossians 2:9Matthew 28:19

In fairness: They are right and reverent that God is one and that idolatry is a deadly sin (Deut 6:4; Exod 20:3). Their instinct to protect God's uniqueness is biblical; the misunderstanding is treating the Trinity as three gods rather than one God in three persons.

Jesus (Isa) is a mighty prophet and the Messiah — virgin-born, sinless, a healer, word and spirit from God, who will return — but strictly a human messenger, not divine and not the Son of God.

Their basis
Quran 4:171 ('the Messiah... was only a messenger of God'); 5:75 ('the Messiah... was no more than a messenger; messengers passed away before him'); 19:30-34 has the infant Jesus declare himself a servant and prophet of God. Calling God's servant His 'son' is seen as unfitting for the Creator.

Scripture answers
Jesus accepted worship, forgave sins as only God can (Mark 2:5-7), and identified Himself as the way, truth, and life (John 14:6). Peter's confession — 'You are the Christ, the Son of the living God' — is blessed by Jesus, not corrected (Matt 16:16-17). To honor Him merely as prophet while denying His deity is, John says, to fail to have the Father either (John 5:23; 1 John 2:23).

John 14:6Matthew 16:16Matthew 16:17Mark 2:5Mark 2:6Mark 2:7John 5:231 John 2:23

In fairness: Islam honors Jesus more than many skeptics do — affirming His virgin birth, sinlessness, miracles, messiahship, and second coming. That reverence is a genuine and hopeful common starting point; the tragedy is stopping at 'prophet' when He claimed and proved far more.

Jesus was not crucified and did not die on the cross; God rescued Him and raised Him to Himself, and it only appeared to onlookers that He was killed (a substitution).

Their basis
Quran 4:157-158: 'they did not kill him, nor crucify him, but it was made to appear so to them... God raised him up to Himself.' Underlying it is the conviction that God would not abandon His honored prophet to such a shameful death.

Scripture answers
The crucifixion is the most historically attested event of Jesus' life, foretold and fulfilled: 'Christ died for our sins... was buried... was raised on the third day' (1 Cor 15:3-4). Isaiah 53 foresaw the pierced, suffering Servant; John, an eyewitness, records the spear and blood and water (John 19:33-35); Jesus said 'It is finished' (John 19:30). Far from shame, the cross is God's power and wisdom (1 Cor 1:23-24) — and without His death and resurrection there is no forgiveness (Heb 9:22; Rom 4:25).

1 Corinthians 15:31 Corinthians 15:4Isaiah 53:5John 19:30John 19:33John 19:34Hebrews 9:22Romans 4:25

In fairness: The motive — that God would not let His prophet be humiliated — springs from a real reverence for God's honor. Scripture answers that the cross is not God's defeat but His deepest glory and love (John 3:16; Rom 5:8): the shame was ours, borne willingly by Him.

Muhammad is the final 'Seal of the Prophets,' and the Quran is God's perfect, final, uncorrupted word that supersedes and corrects the earlier Scriptures, which are held to have been altered (tahrif).

Their basis
Quran 33:40 names Muhammad the Seal of the Prophets; 7:157 speaks of the unlettered prophet 'found written' in the Torah and Gospel. Some cite Deuteronomy 18:18 (a prophet like Moses) and John 14-16's Paraclete as predictions of Muhammad.

Scripture answers
Paul pronounces a curse on any later 'gospel' — even from an angel — contrary to the one delivered (Gal 1:8). Jesus said the promised Helper is the Holy Spirit, whom the Father sends, who was given at Pentecost and dwells in believers (John 14:26; 16:13; Acts 2) — not a future prophet. God's word does not fail or pass away (Matt 24:35; Isa 40:8; 1 Pet 1:25), and Revelation warns against adding to it (Rev 22:18-19). The 'prophet like Moses' is fulfilled in Jesus (Acts 3:22-23).

Galatians 1:8John 16:13John 14:26Matthew 24:351 Peter 1:25Revelation 22:18Acts 3:22

In fairness: Their high reverence for revelation, and the concern that sacred texts can be mishandled, is not baseless — Scripture itself warns against twisting God's word (2 Pet 3:16). But the manuscript evidence shows the New Testament we hold is the one the apostles wrote.

Salvation is by submission to God and a life of good deeds, with no substitutionary atonement — one's deeds are weighed in the balance, and final acceptance rests on God's mercy, leaving no settled assurance.

Their basis
Quran 23:102-103: 'those whose scales are heavy — they are the successful; those whose scales are light — they have lost their souls.' The Five Pillars and obedience to God's law, joined to Allah's mercy, are the path; there is no need for a mediating sacrifice.

Scripture answers
Scripture teaches no one is justified by works of the law (Rom 3:20); salvation is a gift, 'by grace... through faith... not a result of works, so that no one may boast' (Eph 2:8-9; Titus 3:5). Christ's one sacrifice, not our scale of deeds, reconciles us (Rom 5:1,8-9; Heb 10:14), and believers may KNOW they have eternal life (1 John 5:13) — assurance grounded in Him, not in the uncertainty of a final weighing.

Ephesians 2:8Ephesians 2:9Titus 3:5Romans 3:20Romans 5:1Hebrews 10:141 John 5:13

In fairness: They rightly hold that God is merciful and that a real faith bears the fruit of obedience, prayer, fasting, and generosity — disciplines many Christians neglect. The gospel agrees deeds matter (Jas 2:17) — but as the fruit of salvation received by grace, never its purchase price.