Acts, chapters 23 & 24

“At the same time [Felix] was hoping that Paul would give him money. For that reason, he sent for him even more frequently and conversed with him. But when two years had elapsed, […] he left Paul in custody.”
~Acts 24:26,27

How can a Christian distinguish between giving a bribe and tipping an official to ensure a service is rendered?
The Bible clearly condemns bribing. (Ps. 15:1,5)
But what could be considered a bribe in one country, could be considered a customary tip in another.
I remember a traffic officer in Mexico who would not release us until my aunt (not one of Jehovah’s Witnesses), implied she would give him a tip.
On other occasions in which my husband and I were pulled over, we accepted citations for minor traffic infractions instead of handing over any cash.
But it is true that many government officials, especially in developing nations, do not make enough money to live on, so whether or not a Christian decides to tip one is a matter of personal conscience. (Mark 12:17; 1 Cor. 10:31-33)
It would be blatantly wrong to give something with the intent of evading justice or seeking preferential treatment over others(Deut. 16:19; Matt. 7:12)
Despite his reputation for corruption, Felix as governor did have a legal right to hold Paul indefinitely without handing him a verdict. (Watchtower. 2001, December 15. “I Appeal to Caesar!”)
If Paul had caved in to bribing him, he would have been breaking Roman law.
As Christians, we find comfort in knowing that Jehovah will bring ultimate justice and he cannot be bought. (Deut. 10:17)

1 Samuel, chapters 10-13

“Here I am. Testify against me before Jehovah and before his anointed one: Whose bull or whose donkey have I taken? Or whom have I defrauded or crushed? From whose hand have I accepted a bribe to make me look the other way? If I have, I will restore it to you.”
~1 Samuel 12:3

Samuel had a clean conscience because he maintained sincere, wholehearted worship of Jehovah throughout his life.

The people he served were able to testify: “You have not defrauded us or crushed us or accepted anything at all from anyone’s hand,” (1 Sam. 12:4).

While leaders of false religion use their religious institution as a sort of business and as a means to sustain themselves materially, true believers do not take advantage of their spiritual brothers to gain material benefits (Matt. 10:8; 1 Pet. 5:2).

We must be careful to always keep our form of worship free of commercial or potentially corrupt personal interests in order to not imitate the oppressive attitude of hypocritical church leaders (John 2:15,16).

Then we should ask ourselves: can I swear before Jehovah, like Samuel, that I have defrauded no one?