There is always the danger that we may just do the work for the sake of the work. This is where the respect and the love and the devotion come in - that we do it to God, to Christ, and that's why we try to do it as beautifully as possible.
Gospel text (Mt 6:1-6.16-18): Jesus said to his disciples, «Be careful not to make a show of your righteousness before people. If you do so, you do not gain anything from your Father in heaven. When you give something to the poor, do not have it trumpeted before you, as do those who want to be seen in the synagogues and in the streets in order to be praised by the people. I assure you, they have been already paid in full. If you give something to the poor, do not let your left hand know what your right hand is doing, so that your gift remains really secret. Your Father who sees what is kept secret, will reward you.
»When you pray, do not be like those who want to be seen. They love to stand and pray in the synagogues or on street corners to be seen by everyone. I assure you, they have already been paid in full. When you pray, go into your room, close the door and pray to your Father who is with you in secret; and your Father who sees what is kept secret will reward you. When you fast, do not put on a miserable face as do the hypocrites. They put on a gloomy face, so people can see they are fasting. I tell you this: they have been paid in full already. When you fast, wash your face and make yourself look cheerful, because you are not fasting for appearance or for people, but for your Father who sees beyond appearances. And your Father, who sees what is kept secret will reward you».
Today, Jesus invites us to act always for the glory of God, to please the Father, as this is why we have been created for. This is how the Catechism of the Church confirms it: «God created everything for man, but man in turn was created to serve and love and to offer all creation back to him». This is the meaning of our life and our honor: to be liked by the Father, to please God. This is the example Christ left with us.
Dishonesty of intention would be especially grave and ridiculous if happening in actions such as prayer, fasting or alms, as these are pious and charitable deeds, that is, deeds that —per se— are due to the virtue of religion or deeds we carry out for the love of God.
Therefore, «be careful not to make a show of your righteousness before people. If you do so, you do not gain anything from your Father in heaven» (Mt 6:1). How could we please God if, to start with, we are trying to be seen in order to be praised —first of all— by others? It is not that we have to hide from our fellow men so that they will not see us, but it is rather a question, in the first place, of directly addressing our good deeds to God. It does not matter, nor is it bad others may see us: on the contrary, we may give them example with the coherent testimony of our deeds.
But what it does matter —and a lot!— is that we can see God behind our deeds. We must, therefore, carefully examine our true intentions in whatever we are doing, and see that we are not seeking our own interest, if we are really trying to serve the Lord» (St. Gregory the Great).