Forasmuch then as God gave them the like gift as he did unto us, who believed on the Lord Jesus Christ; what was I, that I could withstand God?

People's New Testament

11:17 What was I, that I could withstand God? All these extraordinary signs were then given in order to show Peter and the Jewish Christians that the Gentiles were also accepted.

Wesley's Notes

11:17 To us, when we believed - The sense is, because we believed, not because we were circumcised, was the Holy Ghost given to us. What was I - A mere instrument in God's hand. They had inquired only concerning his eating with the Gentiles. He satisfies them likewise concerning his baptizing them, and shows that he had done right in going to Cornelius, not only by the command of God, but also by the event, the descent of the Holy Ghost. And who are we that we should withstand God? Particularly by laying down rules of Christian communion which exclude any whom he has admitted into the Church of the first born, from worshipping God together. O that all Church governors would consider how bold an usurpation this is on the authority of the supreme Lord of the Church! O that the sin of thus withstanding God may not be laid to the charge of those, who perhaps with a good intention, but in an over fondness for their own forms, have done it, and are continually doing it.

Matthew Henry's Concise Commentary

11:1-18 The imperfect state of human nature strongly appears, when godly persons are displeased even to hear that the word of God has been received, because their own system has not been attended to. And we are too apt to despair of doing good to those who yet, when tried, prove very teachable. It is the bane and damage of the church, to shut out those from it, and from the benefit of the means of grace, who are not in every thing as we are. Peter stated the whole affair. We should at all times bear with the infirmities of our brethren; and instead of taking offence, or answering with warmth, we should explain our motives, and show the nature of our proceedings. That preaching is certainly right, with which the Holy Ghost is given. While men are very zealous for their own regulations, they should take care that they do not withstand God; and those who love the Lord will glorify him, when made sure that he has given repentance to life to any fellow-sinners. Repentance is God's gift; not only his free grace accepts it, but his mighty grace works it in us, grace takes away the heart of stone, and gives us a heart of flesh. The sacrifice of God is a broken spirit.