After the Reformation in 1517, the following five core theological convictions were identified by the Protestant church as the foundation of doctrine and dogma, grounded in the truth of the Holy Bible. These present the source of spiritual authority, the elements of unquestionable salvation, and the reason for all of this.

Sola Scriptura (Scripture Alone) – The Bible is the sole, inerrant, and final authority for faith and practice. It rejects the idea that church tradition or councils hold equal authority to the written Word of God.

All scripture is given by inspiration of God, and is profitable for doctrine, for reproof, for correction, for instruction in righteousness: That the man of God may be perfect, thoroughly furnished unto all good works. ^{2nd Timothy 3:16-17}

Sola Fide (Faith Alone) – Justification (being declared righteous by God) is received by faith alone, apart from any human works or merit. Humans are justified solely by God’s unmerited favor rather than their own righteousness or efforts.

For by grace are ye saved through faith; and that not of yourselves: it is the gift of God: Not of works, lest any man should boast. ^{Ephesians 2:8-9}

Sola Gratia (Grace Alone) – Salvation is a completely free gift of God, bestowed upon sinners solely by his grace, not earned by human merit. Humans are justified solely by God’s unmerited favor rather than their own righteousness or efforts.

And if by grace, then is it no more of works: otherwise grace is no more grace. But if it be of works, then it is no more grace: otherwise work is no more work. ^{Romans 11:6}

Solus Christus (Christ Alone) – Jesus Christ is the only mediator between God and man, and his sacrifice is the only basis for justification.  Salvation is found in no other name.

Jesus saith unto him, I am the way, the truth, and the life: no man cometh unto the Father, but by me. ^{John 14:6}

Soli Deo Gloria (Glory to God Alone) – Since salvation is of God and from God, all glory belongs to him alone. The purpose of all life and theology is to glorify God, not to promote human beings or church institutions.

For of him, and through him, and to him, are all things: to whom be glory for ever. Amen. ^{Romans 11:36}

 In whom also we have obtained an inheritance, being predestinated according to the purpose of him who worketh all things after the counsel of his own will: That we should be to the praise of his glory, who first trusted in Christ. ^{Ephesians 1:11-12}