VATICAN CITY (CNS) -- Holiness doesn't depend on superhuman powers, but rather demands a heart filled with courage, hope and grace that strives for conversion each and every day, Pope Francis said at his morning Mass.

In fact, holiness is reached by taking tiny steps, like biting your tongue every time there is the urge to gossip or demean somebody, he said May 24 during the Mass in the chapel of the Domus Sanctae Marthae.

"Bite your tongue a little. Your tongue will swell up a bit, but your spirit will be holier," the pope said.

"Holiness is a journey. Holiness cannot be bought, it is not sold" and it is not given away as a reward, he said. It is "walking in God's presence in an irreproachable way."

Every person is responsible for striking out on a path of holiness, he said. "I have to do it, someone else can't do it in my name. I can pray for someone else to be a saint, but he has to take that path, not me."

The holiness Christians must strive for is an "everyday" task often carried out in anonymity, he said.

This journey first demands courage, "the courage to move forward," he said.

That courage is inspired by hope -- the hope "in an encounter with Jesus."

However, people cannot live holy lives on their own. "It is a grace of God and we must ask for it" and be open to receiving it, he said.

Christians must not conform themselves to the world, but must "change one's own heart from within -- in an ongoing, daily intense activity within."

Conversion isn't telling the priest, "Oh father, for me to convert I must do penance -- give me a clobbering," he said.

The process of conversion requires small concrete steps, he said. For example, "If you are able to not speak badly about someone else, you are on the right path for becoming a saint. It's that easy."

Tackle the little things and "don't turn back, always move forward" with hope and strength, he said.