The obvious answer to the question "can we trust the gospels?" is "yes!!". However, this is an excellent book to buttress our confidence in the gospels, their uniqueness, their trustworthiness and the wonderful authentic record of Jesus Christ. This book is easy to read, it is well written and gripping. It has eight shortish chapters and it includes information such as "did the gospel authors know their stuff?". The answer is yes and they could not have known this information in the first-century without being first-hand witness. Peter Williams leads Tyndale House in Cambridge and he is an excellent scholar, including for the NT Greek manuscripts. He is the co-editor of the Tyndale House Greek New Testament.
Evidence such as their knowledge of places including small villages though which Jesus passed, could only have been given with such accuracy through first-hand testimony. I was thrilled to hear that there is information on one other historical figure in antiquity, equivalent to Jesus Christ; that is Emperor Tiberius who is one of the most famous of the Roman Caesars. Peter Williams names that sub-point section "Four is A lot" (pages 39-42) emphasising that four gospels compared to other historical figures in antiquity is a lot. We often take this for granted that we have so much material about Jesus of Nazareth and to do so is a mistake.
2 Timothy 3:16-17 states: "All Scripture is breathed out by God and profitable for teaching, for reproof, for correction, and for training in righteousness, that the man of God may be complete, equipped for every good work".
The Westminster Standards Chapter 1 emphasises the majesty of Holy Scripture in 1:5:
"We may be moved and induced [persuaded] by the testimony of the Church to a high and reverent esteem of the Holy Scripture. And the heavenliness of the matter, the efficacy of the doctrine, the majesty of the style, the consent of all the parts, the scope of the whole (which is, to give all glory to God), the full discovery it makes of the only way of man’s salvation, the many other incomparable excellencies, and the entire perfection thereof, are arguments whereby it does abundantly evidence itself to be the Word of God: yet notwithstanding, our full persuasion and assurance of the infallible truth and divine authority thereof, is from the inward work of the Holy Spirit bearing witness by and with the Word in our hearts.
"The majesty of the style ... the scope of the whole" of Scripture is brought out by this book. It does prove the infallibility of Scripture, that is reserved for the Holy Spirit, but it enriches our appreciation for the transmission of the Greek manuscripts called the Gospels.
My advice is for people to buy this book, read it, enjoy it, and then pick up the gospels to read them again and be thrilled by the life, message and atonement of Jesus the Son of God.