Experts on Lutheran docerine?

My family and I are Southern Baptists. My children are all in the church group knows as AWANAS. (If you are not familiar with AWANAS, go look at the link below, it’s too much to type out here). Anyway my son (age 4) is a member of AWANAS and frequently brings his best friend (age 5) to the AWANAS meeting. This other little boy and his mother (single parent) are Lutheran. I have no issues with this, I personally believe that God doesn’t care what religion you are, and it’s what you believe in your heart that really matters. The Baptist church where we are members does not have an issue with children from other churches attending the AWANA meetings.