What is renewal? We often use certain phrases or terminology to describe the idea of a fresh connection with God. the Bible talks about "times of refreshing".
"But what God foretold by the mouth of all the prophets, that his Christ would suffer, he thus fulfilled. Repent therefore, and turn back, that your sins may be blotted out, that times of refreshing may come from the presence of the Lord, and that he may send the Christ appointed for you..." - Acts 3:18-20
The idea of that refreshing is connected to "repentance" and further attached to the coming Messiah who provided The Way back to the Father through His suffering. I do not read anywhere in the New Testament that repentance after salvation is unnecessary. Whilst at the initial salvation experience one "repents" of the past and the blood of Christ removes our sins, this is in conjunction with the regenerating work of the Holy Spirit that make us children of God.
However, there remains in the ongoing sanctifying work of the Holy Spirit times where we repent of independent and even prideful actions opposing God's plan for our lives. It really is about attitude. A humble reliance and dependance upon God means there are no perfect children of God, but certainly maturing children of God who adjust their lives and thinking, to align with and conform to the Christ within. The better attitude in such areas is not to have a "know it all" attitude.
Therefore, perpetual "refreshing" takes place when we acknowledge our shortfalls and limitations. When that becomes a collective activity and attitude of a church family, the term "revival "is often used. Lets be proactive in remaining refreshed in the Lord!