When Colorado church pastor Jeff Cook saw Muslims choosing to give up luxuries and certain foods over Lent in solidarity with Christians, he was deeply moved. Using the hashtag #Muslims4Lent, hundreds of people chose to make sacrifices in the lead up to Easter, and posted photos to Twitter and Facebook. Cook mentioned the movement in a sermon, and suggested that he might take part in Ramadan in response; a few months later, he was called up on his pledge by one of his parishioners.

"Somebody in my congregation held me to it," he told Christian Today. "So I started thinking it through some more, and I thought 'Yeah, I think this will be for me'." So, from June 18 to July 17, Cook is fasting over lunchtimes. He isn't fully taking part in Ramadan, which requires followers of Islam to fast between sunrise and sunset, because he thinks that would be a disservice to devout Muslims.

"I don't feel like it's my celebration to embrace in the full way that the devout would," he explained. "I feel that would be an indecency on my part."

Cook is not alone. Many Christians have decided to take part in Ramadan this year, using a new hashtag, #Christians4Ramadan. "Each participant brings their own unique touch – some fasting for the whole month, others for a day, and some not at all," Sarah Ager, a Muslim who leads the Interfaith Ramadan project, says. "Others are using the opportunity to raise money for charity, including persecuted Christians and Muslims abroad."

Ager says the movement hopes to bring people of different faiths together. "It is all too easy for individuals to feel helpless against a backdrop of seemingly endless global violence, which is all too often rooted in religious divisions," she explains. "Social media-aided initiatives...are a brilliant way of uniting individuals from around the world who are seeking, not only to deepen their understanding of their neighbours, but to work together towards shared goals of co-existence and interfaith co-operation."

It is not enough to simply read about Islam, Ager says, but we need to engage with one another on a personal level. Fasting alongside each other "provides an opportunity for Christians and Muslims to support one another through a shared physical experience, one which has the core aim of bringing about spiritual change for the better," she adds, noting that abstaining from food for prayer is a tradition shared by both Christians and Muslims.

Interfaith activist and former director of the Christian Muslim Forum, Julian Bond, was one of the early adopters of the Christians for Ramadan movement. He has chosen to fast on three separate days over Ramadan on behalf of a Muslim friend who is unable to do so due to health problems. He is also reading the Quran, and tweeting a verse from it each day. He wants to "engage as deeply as possible" with those of other faiths, he says, to combat stereotypes –  particularly of Muslims – which have been growing since 9/11.

"It's about being able to speak from an informed position to encourage others, that they don't have to go as far as me, but if they want to – it's safe," he adds. "It's about building relationships with other people".

Wanting to reach out to Muslims and build trust between different faith communities are key objectives of the movement. Katy Niles, a Christian living in LA and taking part in the project, was also inspired by Muslims who engaged with Lent. "We don't have to accept the stereotypes that news media incorrectly portrays. We can connect with people and recognise we have much more in common than our differences," she told Christian Today.

"It's more important now to bring about interfaith dialogue because we can't strengthen our communities and bring about peace on our own. What a model for the world it would be, [and] has been for me and my friends, if different religions began sharing food, getting along, coming together to offer people what we so desperately need – acceptance, love, traditions, family."

Of course, there will be those who criticise Christians for taking part in Ramadan, and question whether it's necessary to actually engage in Muslim practices in order show love. Niles agrees that it's possible to "love anybody and still hold true to who you are and what you believe". However, she says she wanted to repay the kindness that Muslims showed during Lent. She also believes that in participating in different religious traditions, she has strengthened her own spirituality. "Walk a mile in another person's shoes, and you learn a lot – not just about the other person, but about yourself. I've made some great self discoveries during this holiday – ones that centre on my spiritual well-being, my mental well-being, and my physical well-being."

"If people who love Jesus made it a point to say we have had real difficulty with the Arabic world, we've done quite a bit to create tension and division, but we're going to actively do positive things to re-establish those relationships to create an atmosphere of grace and trust, I imagine that's something the Church could do with more of," Cook says. He says he's had an incredible amount of support from Muslims who are delighted he's joining them in fasting.

Ager, too, is clear that the mutual encouragement people of different faiths are finding through engaging with one another's beliefs is compelling. "For me, the most beautiful aspect of both movements [Muslims for Lent and Christians for Ramadan] has been how those participating have gone from strangers only a few weeks and months ago, to friends, or even prayer buddies, who help one another stay strong in their own respective faiths," she says.

"Bridge building can and should be done at any time in the year, and it doesn't have to involve participating in one another's practices in order to succeed, however, the commonalities between Ramadan and Lent for Muslims and Christians respectively make them ripe for this sort of reciprocal interfaith initiative."

For Niles, the experience has been transformative, and she believes she's putting into practice the prophet Isaiah's call to be a "voice for the voiceless". "I'm simply learning to meet others where they are. And it has immensely changed my life for the better," she says.

"I don't get emotional about a lot of things, but this Friday, when my Jewish and Christian friends come together to break fast at a Muslim's home during an Iftar, my eyes will probably well up and I'll get goosebumps again. Thousands of years of war and violence. And then here we are...16 of us in a home breaking bread together, saying: 'I respect you. I can eat with you. I can share a meal with you. Yes, we might see the world in a different lens, but you're human. I'm human. Let's celebrate that.'"