Your prayer for those who are seeking salvation is good and right, and it reflects the very heart of God who desires that many should be saved and come to know His mercy.
Scripture is clear that salvation is through Jesus Christ alone. As you quoted from Romans, if you confess with your mouth that Jesus is Lord and believe in your heart that God raised Him from the dead, you will be saved. With the heart one believes and is justified, and with the mouth one confesses and is saved. This faith is not empty words, but is joined to true repentance, to turning from sin and bringing forth fruits worthy of repentance, and to following and obeying Christ with a humble heart that condemns its own sin and seeks His forgiveness. Nothing is of ourselves, but all is of God who in His mercy delivers us, and even after we believe we have need of steadfast faith that we may not be shaken.
We join you in prayer for all who are searching. Father, we ask in the name of Jesus that You would draw each seeking heart to Yourself. Grant them grace to confess Jesus as Lord, to believe truly that You raised Him from the dead, and to turn from their sins. Forgive them, make them partakers of Your Holy Spirit, and give them a new life of faith, purity and good works. Keep them in Your mercy and lead them to walk faithfully with Christ all their days. Amen.
It is wise counsel to urge new seekers to read and study the Gospels, beginning with John, that they may come to know Christ as He is revealed in His word. May the Lord use your witness and your prayers to bring many to conversion and healing, and may those who believe continue as examples in word, in conduct, in love, in faith and in purity.