From a young age, God placed a burden in the hearts of Javier and Jeanette for missions and discipleship in Mexico. Even before meeting each other, they both began to step out as pioneers in missionary work, responding to God’s call as singles. Eventually, they met while preparing to dedicate themselves to full-time missions, initially focusing their efforts in northwestern Mexico.

In 2004, they got married and have since served God together in the mission field. Today, they continue this calling as a family, alongside their three children, forming what is now the Leyva García family.

It was in 2012 that they met John and Rachel Reaser while partnering with a foreign missions team for a short-term outreach alongside a local church in the Mazatlán area. By 2014, Javier and Jeanette had become volunteers in the missions model promoted by the Reasers. Over time, their passion and commitment to this vision grew deeply, leading them to formally join the Reaser team to help bring to life the vision that God had placed in their hearts: "Healthy pastors and thriving churches throughout Mexico"—a vision the Leyvas embraced as their own.

In 2016, the Reasers and the Leyvas began laying the tangible and intangible foundations of what is now known as Shoulder to Shoulder Mexico. To this day, it has been an honor for Javier and Jeanette to be part of this project with the mission of “serving and empowering the local church”. They have witnessed firsthand the powerful impact on local churches and their communities when God, through STS, serves, equips, and empowers the pastors who lead them.