I say the truth in Christ, I lie not - This is one of the most solemn oaths any man can possibly take. He appeals to Christ as the searcher of hearts that he tells the truth; asserts that his conscience was free from all guile in this matter, and that the Holy Ghost bore him testimony that what he said was true. Hence we find that the testimony of a man's own conscience, and the testimony of the Holy Ghost, are two distinct things, and that the apostle had both at the same time.

As the apostle had still remaining a very awful part of his commission to execute, namely, to declare to the Jews not only that God had chosen the Gentiles, but had rejected them because they had rejected Christ and his Gospel, it was necessary that he should assure them that however he had been persecuted by them because he had embraced the Gospel, yet it was so far from being a gratification to him that they had now fallen under the displeasure of God, that it was a subject of continual distress to his mind, and that it produced in him great heaviness and continual sorrow.

I say.

Romans 1:9 For God is my witness, whom I serve with my spirit in the gospel of his Son...

2 Corinthians 1:23 Moreover I call God for a record on my soul, that to spare you I came not as yet to Corinth.

2 Corinthians 11:31 The God and Father of our Lord Jesus Christ, which is blessed for ever more, knows that I lie not.

2 Corinthians 12:19 Again, think you that we excuse ourselves to you? we speak before God in Christ: but we do all things, dearly beloved...

Galatians 1:20 Now the things which I write to you, behold, before God, I lie not.

Philippians 1:8 For God is my record, how greatly I long after you all in the bowels of Jesus Christ.

1 Thessalonians 2:5 For neither at any time used we flattering words, as you know, nor a cloak of covetousness; God is witness:

1 Timothy 2:7 Whereunto I am ordained a preacher, and an apostle, (I speak the truth in Christ...

1 Timothy 5:21 I charge you before God, and the Lord Jesus Christ, and the elect angels...

my conscience.

Romans 2:15 Which show the work of the law written in their hearts, their conscience also bearing witness...

Romans 8:16 The Spirit itself bears witness with our spirit, that we are the children of God:

2 Corinthians 1:12 For our rejoicing is this, the testimony of our conscience, that in simplicity and godly sincerity, not with fleshly wisdom...

1 Timothy 1:5 Now the end of the commandment is charity out of a pure heart, and of a good conscience, and of faith unfeigned:

1 John 3:19-21 And hereby we know that we are of the truth, and shall assure our hearts before him...

Of Predestination
Eph. i. 11.--"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."--Rom. ix. 22, 23.--"What if God, willing to show his wrath and to make his power known, endured with much long-suffering the vessels of wrath fitted to destruction, and that he might make known the riches of his glory on the vessels of mercy which he had afore prepared unto glory." In the creation of the world, it pleased the Lord, …
Hugh Binning—The Works of the Rev. Hugh Binning

Concerning God's Purpose
1. God's purpose is the cause of salvation. THE third and last thing in the text, which I shall but briefly glance at, is the ground and origin of our effectual calling, in these words, "according to his purpose" (Eph. i. 11). Anselm renders it, According to his good will. Peter Martyr reads it, According to His decree. This purpose, or decree of God, is the fountainhead of our spiritual blessings. It is the impulsive cause of our vocation, justification, glorification. It is the highest link in …
Thomas Watson—A Divine Cordial

Letter Lxxxv. To Paulinus.
Paulinus had asked Jerome two questions, (1) how can certain passages of scripture (Exod. vii. 13; Rom. ix. 16) be reconciled with Free Will? and (2) Why are the children of believers said to be holy (1 Cor. vii. 14) apart from baptismal grace? For the first of these questions Jerome refers Paulinus to his version (newly made) of Origen's treatise, On First Principles. For the second he quotes the explanation of Tertullian. Written in 400 a.d. 1. Your words urge me to write to you but your eloquence …
St. Jerome—The Principal Works of St. Jerome