We don't make a practice of tearing our clothing when we ask God for forgiveness any more. Though I bet that if we did, we'd take it a little more seriously- or put on something that was worn out.
The Israelites use to come before the Lord when asking God's forgiveness and rip their outer tunic as a symbol of mourning what they had done. Though it started out as being done during a time of strong emotion (Gen 37:29, Ezra 9:3, Isaiah 37:1), it is mostly done today only at funerals for Jews and has been reduced to a small portion of cloth or a black ribbon they wear.
But, why? Why did they do that at all? To show brokenness of self and the need for God to intervene. It was a practice in faith- in essence. Tearing your clothes shows coming to the end of one's self and the need for a greater power - God - to intervene and take care of them: Even to take care of the basic need of covering one's self. It was a great physical reminder of their spiritual state. But man, as we well know, can take anything and forget the true point....
Tear your hearts,
not just your clothes,
and return to the LORD your God.
For He is gracious and compassionate,
slow to anger, rich in faithful love,
and He relents from sending disaster.
Joel 2:13
We must never forget the point of why we do what we do: Be it saying the Lord's Prayer, reading our daily devotional, giving to the poor, or taking the Lord's Supper. It is our hearts He wants. Not our routine.
Think about what you are doing with/for the Lord today... and make sure your heart is in it.