Acts 2:22 refers to Jesus as a man approved of God among the people and if we are followers of God (Ephesians 5:1), we need to be approved of God amongst his people as well. The Bible counsels us to study the Word of God to show ourselves approved unto God and as workmen/workwomen, we need not be ashamed, but rightly divide [explain] the word of truth (2 Timothy 2:15).
The ones who are approved unto God are not ashamed of God, but they faithfully and diligently study and teach (explain) the word of truth unashamedly.

Points to ponder:
Am I approved unto God? Are you approved unto God? i.e., Do we study the word of God and do we work for him in explaining it without any shame, though people may despise and mock us? In other words, Are we like Jesus, one approved of God among his people?

Acts 2:21-22 (KJV)
21 And it shall come to pass, that whosoever shall call on the name of the Lord shall be saved.
22 Ye men of Israel, hear these words; Jesus of Nazareth, a man approved of God among you by miracles and wonders and signs, which God did by him in the midst of you, as ye yourselves also know:

2 Timothy 2:15 (KJV [NLT])
15 Study to shew thyself approved unto God, a workman that needeth not to be ashamed, rightly dividing [explaining] the word of truth.