There are really on two religious groups: Grace and Works.  Most religions are works religions.  Where Christianity is a one of Grace.  God is wooing us, and offering us his grace, he sent his only Son as the sacrifice. All we have to do is accept it and repent of our sins and seek God and His Righteousness. 

So if you come in contact with anyone, and you don't feel qualified to witness, you can always tell them your testimony.  Let them know what Christ has done for you!

Offer to pray for them.  If they are offended, then always apologize for offending them and try to leave a good witness for Christ. (You may be leaving a seed).

This are my notes of what Doris Slappey has shared with us, during a witnessesing class.