Grace plays a big part in in shaping our apologetic. In fact, showing grace and love is our greatest apologetic. With it, we’d really have no Good News and no Jesus to faithfully share as everything in the Christian faith revolves around grace and love. Remember Jesus’ greatest commandments:
Matthew 22:35-40 NIV
 One of them, an expert in the law, tested him with this question:  “Teacher, which is the greatest commandment in the Law?”  Jesus replied: “ ‘Love the Lord your God with all your heart and with all your soul and with all your mind.’  This is the first and greatest commandment.  And the second is like it: ‘Love your neighbor as yourself.’  All the Law and the Prophets hang on these two commandments.”
What are these commandments without grace and without love? Also:
Matthew 5:43-47 NIV
 “You have heard that it was said, ‘Love your neighbor and hate your enemy.’  But I tell you, love your enemies and pray for those who persecute you,  that you may be children of your Father in heaven. He causes his sun to rise on the evil and the good, and sends rain on the righteous and the unrighteous.  If you love those who love you, what reward will you get? Are not even the tax collectors doing that?  And if you greet only your own people, what are you doing more than others? Do not even pagans do that?
Show me the gospel without grace and love and I’d probably respond (if I wasn’t a believer) with “an eye for an eye and a tooth for a tooth” as Jesus says not to do. We’d all be Pontius Pilate asking “What is truth?” and walking away without an answer. What is truth without grace? What is truth without love? It’s a pragmatic fist to the face, that’s what it is.
Grace and love play a huge part in apologetics and in communicating the gospel.