"Sometimes our non-Catholic friends suspect us of sinning against the first commandment because of the honor we pay to the saints. This accusation would be true if we paid to the saints the divine worship that is due to God alone. But we do not, not if we are in our right minds. Even the honor which we pay to Mary, the Blessed Mother of God, surpassing as it does the reverence we pay to the angels and the other canonized saints, is still of an entirely different nature from the adoration which we give, and may give, only to God.
When we pray to our Blessed Mother and to the saints in heaven (as we should) and beg their help, we know that whatever they may do for us will not be done of their own power, as though they were divine. Whatever they may do for us will be done for us by God, through their intercession. If we value the prayers of our friends here upon earth and feel that their prayers will help us, then surely we have the right to feel that the prayers of our friends in heaven will be even more powerful. The saints are God's chosen friends, heroes in the spiritual combat. It pleases God to encouraage our imitation of them and to show his own love for them b dispensing his graces through their hands. Nor does the honor we show to the saints detract one whit from the honor that is due to God. The saints are God's masterpieces of grace. When we praise them, it is God--who made them what they are--whome we honor most. The highest honor that can be paid to an artist is to praise the work of his hands.
We honor the statues and the pictures of the saints, yes; and we venerate their relics. But we are not adoring these representations and relics. No more so than a hardheaded businessman is adoring the picture of his sainted mother before which he places a fresh flower every morning, or the lock of whose hair he carries reverently in his wallet. And when we pray before the crucifix or the image of a saint, in order to better fix our mind upon what we are doing, we are not so stupid (let us hope) as to suppose that the plaster or wooden image has in itself any power to help us. That would be a sin against the first commandment, which forbids the making of images in order to adore them. But we do not, of course, adore them."
--The Faith Explained, by Fr. Leo J. Trese