It is very common for people to judge their self-worth and personal achievements relative to those of others. In fact, whether we like to admit it or not we may even wish that someone else achieves less so that we can be in a higher position.
For many of us the source of our motivation to pray is our belief that we have the power to engage God for our needs. Nevertheless, moments where we fear that our personal lacking and sin will cause God to turn us a deaf ear cannot be escaped.
Some people worship God because they fear the consequences of disobedience, Others pine for a true devoutness to God never feeling that they achieved it.