By Rabbi Aharon Seleh: The Ben Ish Chai quotes a fascinating Zohar which explains how important it is to do the mitzvot with joy and to sing and praise Hashem.
The Zohar says there are 2 camps in the impure forces. One is responsible for all the frivolous parties in the world: the bars, night clubs etc..The other one is responsible for the crying and sadness in the world. In general these forces do all in their power to hold back our prayers from ascending. But when these forces clash against each other, there is nothing holding back our prayers from being immediately accepted. That’s the most opportune time to make a prayer. When we do our mitzvot with joy and singing, especially on Shabbat where we have a festive meal, the camp responsible for sadness thinks the other camp is responsible for the joy and it goes to wage war against it. Our tefillot then can ascend immediately!
The Ben Ish Chai brings a parable where a man is being followed by a lion. He sees a bear up ahead. He climbs a tree and throws a rock at the bear. The bear turns around and only sees the lion. It attacks! The man is able to escape.
Do every mitzvah with joy, and continuously sing to Hashem, תפלת תעלה לשמי מרומי×! Your tefillot will ascend without any obstacles.
Shabbat Shalom