The world isn’t being changed by “altar calls.” ObeyGC2 is an alter call.
The word “repent” actually means to change one’s mind. The idea is to turn around; change direction. At the bottom of this idea is a change from serving oneself and one’s own desires and values and give one’s allegiance instead to Christ. His values, His desires, His direction are adopted as one’s own. This can be viewed as a change from pride to an attitude of humility; from seeing oneself as king to seeing Christ as King. That means all that I am, all that I’m not, all that I have, all that I hope to be are His. It also means I actively seek what His desires for me are. The best place to find this sort of information is in the Bible. The best summary of this can probably be found in the Great Commission and the Great Commandment.
Matt 18:1-4
18:1 At that time the disciples came to Jesus and asked, “Who is the greatest in the kingdom of heaven?”
2 He called a little child and had him stand among them. 3 And he said: “I tell you the truth, unless you change and become like little children, you will never enter the kingdom of heaven. 4 Therefore, whoever humbles himself like this child is the greatest in the kingdom of heaven.
2 Tim 3:16-17
16 All Scripture is God-breathed and is useful for teaching, rebuking, correcting and training in righteousness, 17 so that the man of God may be thoroughly equipped for every good work.