This is a great question. The truth is, however, that we can never fully understand the ways of Hashem. The main intention in the words of our sages that if one refrains from speaking lashon hara and other sins, one has an easy parnassah, etc is that these sins actually “stuff up the pipelines” of blessing from entering the world. Meaning, even if one is meant to receive blessing, sins have the ability to block these blessings from entering the world. Consequently, if one removes these “blockages,” he will gain the blessing that he is meant to have. Still, we do not know why Hashem grants certain blessing and ease to some people, while others have it difficult in life. Although there are many explanations, such as “gilgulim” or atonement for sins in past lives, or that Hashem wishes to save one’s merits to be enjoyed eternally in the World to Come, we do not know how to apply these ideas to particular situations. One thing we do know is that whatever Hashem does is for the good for each person at all times. This is a large topic and must be discussed at length. If you would like, please respond and we will try to provide with a list of sources the elaborate on this subject.