Although the Bible mentions angels over 250 times, the references are usually incidental to some other topic. Learning what the Bible has to say about angels can certainly aid in an understanding of God and His ways, but what is learned about the angels themselves must be drawn from implicit, rather than explicit, descriptions.
Angels are spiritual beings who have personalities that include emotions (Luke 2:13), intelligence (2 Corinthians 11:3), and wills (2 Timothy 2:26). Satan was an angel who was cast out of heaven along with many other angels who decided to follow him and chose to sin (2 Peter 2:4). In terms of free will, the Bible reveals this was an exercise of their ability to choose (Jude 1:6).
Some scholars believe there was a sort of “probation period” for the angels, similar to the time when Adam and Eve were in the garden. Those angels who did not choose to sin and follow Satan have become the “elect” angels (1 Timothy 5:21), confirmed in holiness. These angels are also referred to as “holy angels” (Mark 8:38) and “holy ones” (Psalm 89:5).
Even if the elect angels are confirmed in their holiness, it doesn’t mean they have lost their free will. Certainly, every living creature has choices to make at any given moment. The holy angels might have the ability to sin, but that does not in any way mean that they will sin.
To help understand this issue, we can consider the life of Christ. Christ was “tempted in every way” (Hebrews 4:15), yet He did not sin. Jesus had the ability to choose whatever He pleased (John 10:17–18). However, Jesus’ first priority was always to please His Father, and that is always what He chose (John 4:34). If Christ, who was 100 percent human (as well as 100 percent divine), could live in a sinful environment and face daily temptation, surely holy angels who live in a purely holy environment can freely choose good over evil. The elect angels praise God because they choose to; they obey God because that is what they desire most to do (see Jonathan Edwards’s Freedom of the Will).
Humans have free will, but they struggle with sin because the human nature is corrupt and bent toward sin. This is why all humans sin (Romans 5:12) and find it much more difficult to “be good” than to “be bad.” The holy angels are without a sinful nature. They are not inclined toward sin but rather toward righteousness, doing everything that pleases God.
In conclusion, it doesn’t actually matter whether or not holy angels have the freedom to sin. They have a free will, but the Bible makes it clear they will not sin. The apostle John, in describing heaven, wrote there will be no mourning, crying, or pain there (Revelation 21:4), and anyone who does evil will never be permitted to enter (Revelation 21:27). The angels who are part of heaven are sinless.
 Got Questions Ministries. (2010). Got Questions? Bible Questions Answered. Bellingham, WA: Logos Bible Software.