"The fruit of the Spirit is...gentleness"
Gentleness is the fifth fruit of the Spirit. Here are two examples of the type of gentleness that Paul is referring to in Galatians (5:23).
The gentlest rabbit I ever met was named Sniffy. Our dad found him one night by the side of the road after he ran across in front of the car. My brother had recently read Watership Down by Richard Adams as well as its sequel—800 pages in less than a month, no small feat for an eight year old. Upon finishing, Ian asked our dad for a pet rabbit. Dad said no but Ian had to have appealed to God. That night when Dad came home, little Sniff sitting wide-eyed, bundled up in his arms, Ian initially thought he was just a stuffed animal. And when his eyes twitched and twinkled (and nose, hence his name), Ian jumped out of his skin. At first we weren't going to keep him, but we quickly fell in love and though he passed away many a year ago, to this day I'll still refer to him as my youngest brother. Sniffy was a precious little guy, always insistent upon being touched and loved before he got fed. The gentleness of God radiated and oozed from his little, brown, rabbit body.
"Howbeit when He, the Spirit of truth, is come, He will guide you into all truth: for He shall not speak of Himself; but whatsoever He shall hear, that shall He speak: and He will shew you things to come." (John 16:13)
The gentlest person, however, that I've met is the Holy Spirit. Whenever I think about Him, if I had to name a quality of His character that stands out to me above all others, it would be His gentleness. The Holy Spirit is the third member of the Trinity and one of His jobs is to transmit to us everything God wants us to have. He is the one who remade our spirit after accepting Jesus and He's the one who leads and guides us as we walk this earth. Everything he does is so, so gentle that it can be easy to miss. In fact, He's so gentle as to be nigh imperceptible. As such, it is tragically easy to offend (see 1 Thessalonians 5:19) and to hurt Him (see Ephesians 4:30). The world certainly doesn't see Him (see John 14:17) and sadly, many Christians don't even know how to relate to Him. If we are to relate to so sensitive a person, then we ourselves must strive, with God's help, to be fashioned into the gentle type of person that the Holy Spirit can freely interact with. I suppose this is why many members of the Body of Christ don't see the Holy Spirit like they could and should. People tend to be short and harsh in their dealings with others--and even with God. And all along, the Holy Spirit pines away in the background of their life wanting a fuller fellowship with them.
The good news is that Jesus has given us the Holy Spirit as a gift (see Acts 2:38). Ask the Holy Spirit directly and politely to show to you and reveal in you His gentleness.
And maybe, like Sniff, show Him some love before He does anything in answer to that prayer.