Grace was born in Kanyigo Bukoba, Tanzania. She is known as a leader, organizer, preacher, and teacher. Ernest Bayona, Grace's father, a school headmaster, was one of the outstanding Lutheran teachers in Tanzania. Grace was brought up in a Christian context with a clear emphasis on Christian values. Her family integrated religious and educational activities as part of the cultural activities of a headmaster's household.

Grace accepted Jesus Christ as Lord and Savior in 1978 during her early years in secondary school. She was active in the Christian Union Groups where she developed a strong interest in serving the Lord as an evangelist. After high school she was called to serve with AE Tanzania and specifically to establish a youth ministry.

Grace attended Daystar University College, Nairobi, Kenya where she received a degree in Communication and Christian Ministries. While a student she was secretary of the Daystar Evangelistic Team and organized two international trips to Uganda and Tanzania. At Daystar she was awarded with the Daystar University President's Award as best student.

She went to Wheaton Graduate School for her degree in Educational Ministries. At Wheaton she served as the president of the International Student Fellowship.

Grace has taken a leading role in planning many evangelistic events in Tanzania and Africa. Since she joined AE, Grace has never stopped the fire and the desire to see people come to faith in Jesus. She is respected for her commitment and dedication to evangelizing the cities of Africa in partnership with the churches. A Lutheran Evangelical, Grace is dedicated to marriage counseling, training, and mentoring.