We need God's help because we are creatures; because we have a fallen human nature and because we are constantly being besieged by the evil spirit.
Fr. John A. Hardon, S.J.
The popular understanding of prayer as asking for God's help is correct. Most of the prayers in the Scriptures are petitions. Most of the prayers of the liturgy are the same. Even the acts of adoration or love are always implicit petitions. Why is this so? Why do we need to ask for God's help? The reason is the obvious one: because we need that help. However, since we are talking about God and God is not obvious, this cannot be all that obvious as it may seem.
The first reason then that we must pray for help is because we are creatures whom God has raised to an "above-creaturely" destiny. Sometimes I think we should more often use the expression "supercreaturely" or "supercreated" instead of the by now prosaic "supernatural." We have been destined for heaven but heaven is not natural to anyone – except God!
Consequently, although having been destined for heaven – and what could be clearer – we are not there yet and cannot get there by merely human or created means. We need what we callgrace which could be described as what we need but do not of ourselves possess in order to reach the heavenly beatitude for which we were made. What we have is nature; where we are going is heaven; what we need is grace.