The scribes and Pharisees question what authority Jesus has to do the things he has been doing in the temple. Jesus knows their duplicity and exposes it by asking them a question in return, which they are unwilling to answer.
We take this as an illustration of the battle we as believers have between the spirit, which is willing to follow Christ, and the flesh, which desires to seek its own pleasures. We look at the area of spiritual warfare, taking our prayer life as an example, and see how this works out in practice.
If we do not have this inner struggle, it may well be that we are not believers at all. In both cases, believers and unbelievers are urged to come to Christ for strength to overcome the flesh in the one case and for repentance leading to eternal life in the other.