As a Christian, you’ve been commanded to preach the Gospel and to make disciples. The most important thing to remember when doing that is to speak the Word of God. It is the Word of God that’s living and active, sharper than any two-edged sword, piercing to the division of soul and of spirit, of joints and of marrow, and discerning the thoughts and intentions of the heart. God can use your testimony on how you got saved, but make sure you're speaking His Word and not your opinions.