15 Since I was so sure of your understanding and trust, I wanted to give you a double blessing by visiting you twice- 16 first on my way to Macedonia and again when I returned from Macedonia. Then you could send me on my way to Judea. 17 You may be asking why I changed my plan. Do you think I make my plans carelessly? Do you think I am like people of the world who say "Yes" when they really mean "No"? 18 As surely as God is faithful, our word to you does not waver between "Yes" and "No." 19 For Jesus Christ, the Son of God, does not waver between "Yes" and "No." He is the one whom Silas, Timothy, and I preached to you, and as God's ultimate "Yes," he always does what he says.
Matthew Henry's Commentary on 2 Corinthians 1:15-19
Commentary on 2 Corinthians 1:15-24
(Read 2 Corinthians 1:15-24)
The apostle clears himself from the charge of levity and inconstancy, in not coming to Corinth. Good men should be careful to keep the reputation of sincerity and constancy; they should not resolve, but on careful thought; and they will not change unless for weighty reasons. Nothing can render God's promises more certain: his giving them through Christ, assures us they are his promises; as the wonders God wrought in the life, resurrection, and ascension of his Son, confirm faith. The Holy Spirit makes Christians firm in the faith of the gospel: the quickening of the Spirit is an earnest of everlasting life; and the comforts of the Spirit are an earnest of everlasting joy. The apostle desired to spare the blame he feared would be unavoidable, if he had gone to Corinth before he learned what effect his former letter produced. Our strength and ability are owing to faith; and our comfort and joy must flow from faith. The holy tempers and gracious fruits which attend faith, secure from delusion in so important a matter.