It can be tempting to think that if we pray the Rosary every day we are instantly holy.
Similarly, if we fast from meat every Friday of the year, it doesn't not mean that we are devout Catholics.
Performing outward religious acts is certainly an important part of being Christian, but it does not immediately mean that we will go to Heaven.
St. Francis de Sales explains this idea in his book Introduction to the Devout Life:
One man sets great value on fasting, and believes himself to be leading a very devout life, so long as he fasts rigorously, although the while his heart is full of bitterness;--and while he will not moisten his lips with wine, perhaps not even with water, in his great abstinence, he does not scruple to steep them in his neighbour's blood, through slander and detraction.
Another man reckons himself as devout because he repeats many prayers daily, although at the same time he does not refrain from all manner of angry, irritating, conceited or insulting speeches among his family and neighbors. This man freely opens his purse in almsgiving, but closes his heart to all gentle and forgiving feelings towards those who are opposed to him; while that one is ready enough to forgive his enemies, but will never pay his rightful debts save under pressure.
St. Francis de Sales further points out that "all these people are conventionally called religious, but nevertheless they are in no true sense really devout."
Recipe for holiness
The key to being holy lies not in performing many religious actions with an empty heart.
Instead, we are called to give to God our whole being, body and soul. Our actions must be followed-up by a tender heart, a heart on fire with God's love.
If we do pray the Rosary every day, we must let the prayer penetrate our heart and soften it, so that we will help a neighbor in need.